There aren't a lot of those hot shoe mount meters still being made. $225 is a pretty steep price for one, but it will emulate a camera's built-in meter's function, if that's what you want.
All meters of this type measure
reflected light... they measure what's bouncing off the subject and back toward you. So long as the scene in front of the meter is "average" tonality, it will give an accurate reading. But if the scene leans toward one extreme or another, you need to make some adjustments to compensate because the meter itself has no idea what it's "looking at". For example, if you point it toward a black wall, it's going to give you a reading that will cause over-exposure. If, on the other hand, you point it toward a white wall, it will want to under-expose. In other words when things you're photographing are average tonalities, the meter will give you settings to photograph it "average". Or, when the scene and subject are exceptionally dark tonality, a reflective meter will tell you how to make it appear "average". And when the scene is overly light tones, the meter will guide you to make it "average". You have to mentally adjust for these "metering errors", inherent to any reflective metering system.
An alternative is an
incident meter. This type of meter instead measures the strength of the light falling onto the subject, guiding your exposure settings based on that... instead of what's reflected off of and what's influenced by the tonality of the subject and it's surroundings.
Incident meters have to be pointed at the light source, rather than at the subject. So they are separate, handheld meters. Personally I've got several of them... a recent Sekonic L358 is the primary one I use and carry whenever I'm out shooting. This works both as an incident meter with ambient light and can be used to measure flash (which many reflective meters cannot). The Sekonic L358 is no longer made (only avail. used), but the L308 is very similar. The only difference is that the L358 can be fitted with different radio modules to work with wireless flash and studio strobe triggers, such as Radiopopper and Pocket Wizard... The L308 cannot be fitted with radio triggers.
Sekonic L308:
https://www.bhphotovideo.com/c/product/1390250-REG/sekonic_401_305_l_308x_u_flashmate_light_meter.htmlAnother hand-held, incident meter I used for many years is a Sekonic very similar to the modern L398. It's a beautifully made, "old school", analog type meter. One neat thing about it is that it doesn't require any batteries. It uses a photocell that generates it's own small electrical charge when light strikes it (I don't think it's selenium, though it works similarly). The one I have is 30 or 40 years old now and is still perfectly accurate. The L398 is built like a tank and really a thing of beauty compared to the modern plastic/digital readout. Works the same as other incident meters taking ambient light reading, but the L398 cannot be used to measure flash. I still carry mine sometimes when I'm not planning to use flash.
Sekonic L398:
https://www.bhphotovideo.com/c/product/435535-REG/Sekonic_401_399_L_398A_Studio_Deluxe_III.htmlMany of these incident meters also can be used as reflective meters, if wanted, often by swapping out a different sensor diffuser or sliding a different one into place. On the other hand, I don't think there's any way reflective meters can be used as incident meters.
These Sekonic and some other similar meters cost the same or a bit less than that less versatile, reflective hot shoe mount meter you're considering. (I have several of those, too, in my vintage camera collection. Some still work, some don't. I paid far less for them than the price for that new one!)