In the studio, either for commercial product photography or portraiture, I have always used strobes. Modifiers are certainly an important component in controlling the light produced by your strobes. I started out using umbrellas and then graduated to soft boxes. My preference is the soft box because of the degree of light control afforded. Using umbrellas, you can opt to shoot through a white translucent fabric or reflect the light off of the inside of the umbrella back at your subject. With soft boxes, you can choose to diffuse the light using one or more layers of translucent fabric in addition to having the option to use bare bulbs for certain effects. I rarely resort to bare bulbs. If you read tutorials on the Internet, you can find many techniques for adjusting soft boxes or umbrellas including the feathering technique that most portrait photographers use. The size of the umbrella or soft box makes a tremendous difference in your ability to distribute the light evenly and to control the degree of softness. How you position your lights with regard to your subject is critical. The closer you can place the diffused light to your subject, the softer the light. Greater distance from the subject increases harshness. The best reason I can think of for spending a little more money on good strobes vs cheaper models is to increase the range or power of those units. The power is normally referred to in Watt Seconds and the greater the Watt seconds, the greater the range of power you have at your disposal. I recommend main lights at 640 WS or more, and some accent lights having at least 320 WS. While you can actually start out with one or two strobes, I recommend a minimum of three for a studio setup. I do use speed lights on and off camera in mobile situations where lugging strobes and power supply is not practical. I have worked with photographers who use speed lights and smaller soft box accessories. Some have soft boxes that accommodate two speed lights in each box. I have not used these and have no opinion of the results except to say that I haven't heard loud complaints. My use of speed lights is mostly limited to providing fill light in outdoor situations, so referring to someone who uses them more extensively would provide better ideas for you. You don't have to spend a ton of money on strobes. Good professional results can be achieved with new or used units having the desired specifications for a few hundred dollars each. Good reliable units like Alien Bees are affordable. See https://www.paulcbuff.com/Flash-Units/ for examples. RF transmitters are nice and I use them extensively, however, don't forget that most good strobes can be hardwired from your camera for studio use. If you are working in your studio by yourself, the practical and cheaper answer may just be IR units like those from Wein for example. We all have our favorites and firm opinions, so UHH members are certain to give you excellent advice from their extensive experience.

I see you've been getting lots of advice! That's great!
I think you're right, I did reverse my comparisons on my first reply!
Though I don't disagree with dk, I'd like to hear where he's ever needed 640ws? LoL
My lights are 500ws and in a studio, can't remember having them over 1/4 power. Yes, they will recycle faster but that is a LOT of power if you don't shoot large groups, like reunions or baseball teams or daylight groups.
200ws lights are adequate for most portrait or smaller groups like families of say 5.
Depending on how much you can spend, it's hard to know what you will need without a bit of experience first. It's no longer like the old Norman days when everybody ran heads on a power-supply. Lots of great choices today.
Though fairly expensive, do look closely at some of the integrated battery lights like the Godex that Goofy has mentioned.
I'm considering new lights and have looked at the Godex(vs very expensive Profoto) to solve a lot of issues with power and portability.
My recommendation for someone just starting would be a decent used set using convertible umbrellas and can be use reflective or shoot-through. Umbrellas are very cheap and a good way to learn what your modifier demands will become. There are so many kinds of softboxes and octas that it boggles the mind of a seasoned shooter.
Then there are the speedrings. If you change lights or modifiers, you might need all new speedrings to mount the lights.
Personally I would move into it cheaply and conservatively, until you have a good understanding of what you want to create, light-wise.
You haven't mentioned WHAT you want to do yet, or maybe I missed that.
Good luck with this complex subject!!!
Maybe lift some shots off the Internet and post them so we can see your goals.
SS

I see you've been getting lots of advice! That's great!
I think you're right, I did reverse my comparisons on my first reply!
Though I don't disagree with dk, I'd like to hear where he's ever needed 640ws? LoL
My lights are 500ws and in a studio, can't remember having them over 1/4 power. Yes, they will recycle faster but that is a LOT of power if you don't shoot large groups, like reunions or baseball teams or daylight groups.
200ws lights are adequate for most portrait or smaller groups like families of say 5.
Depending on how much you can spend, it's hard to know what you will need without a bit of experience first. It's no longer like the old Norman days when everybody ran heads on a power-supply. Lots of great choices today.
Though fairly expensive, do look closely at some of the integrated battery lights like the Godex that Goofy has mentioned.
I'm considering new lights and have looked at the Godex(vs very expensive Profoto) to solve a lot of issues with power and portability.
My recommendation for someone just starting would be a decent used set using convertible umbrellas and can be use reflective or shoot-through. Umbrellas are very cheap and a good way to learn what your modifier demands will become. There are so many kinds of softboxes and octas that it boggles the mind of a seasoned shooter.
Then there are the speedrings. If you change lights or modifiers, you might need all new speedrings to mount the lights.
Personally I would move into it cheaply and conservatively, until you have a good understanding of what you want to create, light-wise.
You haven't mentioned WHAT you want to do yet, or maybe I missed that.
Good luck with this complex subject!!!
Maybe lift some shots off the Internet and post them so we can see your goals.
SS

Another avenue to explore is “continuous lighting”. I’m not saying it’s the thing to get but it is an option that is getting better all the time. They are not as bright as strobes, not even close, but they also work for you when/if you want to shoot video. Some subjects get startled by the bright flash of strobes, not a problem with continuous. There are great options out there now that LED systems have become so much brighter and cheaper.

I have both. There are things only a strobe/flash can do and, likewise, there are thins you can only do with continuous lights.

Another avenue to explore is “continuous lighting”. I’m not saying it’s the thing to get but it is an option that is getting better all the time. They are not as bright as strobes, not even close, but they also work for you when/if you want to shoot video. Some subjects get startled by the bright flash of strobes, not a problem with continuous. There are great options out there now that LED systems have become so much brighter and cheaper.

I have both. There are things only a strobe/flash can do and, likewise, there are things you can only do with continuous lights.