Can’t say that I’ve looked at that particular store, but there are a TON of sites that sell keycaps. Taihoa is a well known keycap maker, GMK, JWK, etc. The stores that sell the caps are another matter. If you find a set you like on one store, google it and try to find it somewhere else and compare prices.
There are tons of places to get caps. Almost all of the creators I mentioned in the other thread about a keyboard yesterday all have affiliate links to some one or another that sells reputable products. Be sure to check their video descriptions for links.
Yeah so far I have been getting most my caps from Aliexpress. While I would like to credit the original creators of the designs the rest of the markup for “official” is just dumb. I am not paying $300 for key caps.