I'm not attacking anyone particular. I seen this done with many other merchants/smiths/sellers.
One time I had a set of armor that I coupled with a Talon cloak I found. Took some time an made it matching. Because the cloak was limited to human, I stated the armor was also made for human. It took a long time to sell that like over a week or two min. I know how hard it is to sell a heavy piece of suit especially if it is limited to race.
I tried different schemes of setting up sets because I tried to attack this as an artist smith would, so for me it become adding dyes, do modifications. Lots of traveling for the ore. Then measure the person, the travel back for dyes. On and On.
All a merchant has to do is say the armor is size to fit a human, which would probably be most armor out there is Vallaki because Vallaki is mostly human. But they can have a smith resize it up or down. Then the merchant can charge a little extra for the resizing (between 200 to 800 (2d4X100) to be exact according to the PHB page 124 under Full Plate about captured suit).
That is a simple rp fix, instead of saying size to fit.
I know about timezones, because I live on the opposite end of the world to most people on this server.
Noture is right about merchants cant be walmarts. 767 in Barovia. Probably like 1400 to 1500s in Barovia and 1600s in Port Lucine, not 1990s.