Be careful... A Nikkor AF-S VR 105mm Micro lens normally sells new for between $800 to $900 U.S.
One being offered for $500 sounds too good to be true.... ESPECIALLY if it's new!
I found most used ones in reasonably good to excellent, usable condition selling for $600 to $700 U.S.
I did find some used ones online from several reputable, trusted sources for $500 or less, but they were all damaged in one way or another. One had scratched glass, another had heavy fungus, a third had a failed aperture diaphragm... yet another selling for just a little more ($528) is rated "bargain" condition with heavy wear and tear, but functional.
https://www.bhphotovideo.com/c/used/424744/Nikon_2160_105mm_f_2_8G_ED_IF_AF_S.htmlhttps://www.adorama.com/l/Used/Lenses?searchinfo=105mm%20f%2F2.8g%20ed-if%20af-s%20vr%20micro%20nikkor%20lenshttps://www.keh.com/shop/nikon-105mm-f-2-8g-ed-if-af-s-vr-micro-nikkor-lens.htmlYes, if your primary use is portraiture, an 85mm non-macro lens really might be a better choice. I found a number of AF-S NIKKOR 85mm f/1.8G lenses available used for between $350 and $420 U.S., approx. Brand new this lens is selling for $477 (so there isn't a very big discount on the used ones).
https://www.bhphotovideo.com/c/search?Ntt=nikkor%20AF-S%2085mm%20f%2F1.8G&N=0&InitialSearch=yes&sts=ma&Top+Nav-Search=&usedSearch=1https://www.adorama.com/l/?searchinfo=af-s+nikkor+85mm+f%2f1.8g&sel=item-condition_used-itemshttps://www.keh.com/shop/nikon-nikkor-85-mm-f-1-8-medium-telephoto-lens-for-nikon-f-bayonet.htmlNote that the 85mm f/1.8G do not have images stabilization (AFAIK, the only 85mm f/1.8 with it is a Tamron). But I imagine it will focus faster than a macro lens.
If you wanted to be able to use an 85mm for close-ups too, simply get a set of macro extension tubes. The Kenko tube set includes three in 12mm, 20mm and 36mm sizes, sells for $130 new, is well made and fully supports autofocus, aperture control and images stabilization on lenses that have it. I've used macro extension tubes for 25+ years on various systems and currently have a Kenko set and several individual Canon tubes for my Canon camera system (I've got others for use on vintage Nikon gear).
I used a 20mm or 25mm extension on a Canon 85mm f/1.8 lens for this image...
Extension tubes can be used with virtually any lens, to make it focus closer and render higher magnification than it's normally able to do. The extension tube simply goes in between the camera and lens. They are an inexpensive, easy way to shoot close-ups... lightweight and compact, too. The longer then lens focal length, the more extension needed to make it significantly closer focusing. They're probably most ideally used with lenses from around 50mm to 135mm, though I've also used extension tubes with many other focal lengths over the years. They can even be used with "true" macro lenses.
There are also less expensive sets such as Vello ($80) that work fine, but are not as well made and more plasticky than the Kenko (and Canon)... likely less durable.
AVOID any really cheap macro tubes you might see.... Some sets are $25 or even less. But those lack the electronic contacts needed to control auto focus and the lens aperture. Manual focus might not be a deal, but not being able to set the aperture is a serious problem (the cheap sets can work pretty well with lenses that have an aperture control ring on the lens itself... but many modern lenses don't).
In addition to the 85mm f/1.8 + 20mm extension example above....
... for this image I used a 20 or 25mm extension on a 50mm lens:
And here a 25mm extension on a 70-200mm lens....
36mm of extension on a 300mm lens for the following...
And even a 36mm extension on a 500mm lens to make it focus a little closer with a small subject...
Macro extension tubes have no optics in them... just "air". So they have little effect on image quality in most cases. The above image of the rose bud shot with 50mm + extension shows some vignetting and a bit of softening of parts of the image. It's not necessarily a bad thing. I knew that lens set to a large aperture (f/2) would do that and deliberate used it for this image.
There also can be some light "fall off", especially when stacking several tubes for a whole lot of extension. The camera's through the lens metering system takes this into account, though... so will compensate whether setting exposure manually with the on-board meter or using an auto exposure mode. However, if using a separate hand-held light meter, it may be necessary to factor in some extra exposure when using a lot of extension.
Some time back I was fortunate to find a vintage Tamron SP 90mm f/2.5 macro lens at a local secondhand store for all of $20 (like new condition, with hood, caps and matched teleconverter). I've used several of those Tamrons over the years and new it was good... so I grabbed it when I had the chance! It's an "Adaptall 2" lens from the 1980s.... which was a series that uses interchangeable mounts, and so are easily adapted for use on almost any 35mm film or digital camera system. It came with a Nikon F-mount on it. But I wanted to use it on my Canon cameras, so I bought an Adaptall from China (where they are still being made) for all of $40, including shipping. The left hand pic shows the lens with the EOS/EF Adaptall installed, hood reversed for storage and the Nikon F-mount alongside (I also have Adaptalls for five or six other systems). The right hand images shows the lens installed on one of my DSLRs.
That old Tamron 90mm macro lens is only able to do 1:2 or half life size on its own (most modern macro can do full life size, 1:1). Below is a sample images shot with the lens near that 1:2 maximum (left), a second image of the same poppy buds with a 20mm extension added to the lens so it can focus closer (center), and a shot of a bee on an orange poppy (right) using the same lens + extension.
Using a vintage lens like the above... manual focus and manual aperture.... is rather slow. It's made trickier because when you stop down for a little depth of field (f/11 for all three images above), your viewfinder dims down and makes manual focus even more difficult. I probably took around 75 shots of the bees on the flowers to get two or three good ones!
There are many excellent, fully manual, vintage macro lenses available, if you want to try one. Nikon themselves made their 105mm in manual focus & manual aperture versions long before they made them with autofocus and electronic aperture control. Just be aware that those vintage lenses will be slower and more challenging to work with.... though they are often quite capable.