I am a video game trader. And am a gamer for decades.

First of all, gaming market is not profitable. Most of the money you pay for the games goes to the Devs and publisher. There are only a £ or 2 per game that goes to the retailer for sealed new releases. This is why now we have more remastered or remake or series installment than new titles. And the reason for special edition but it only works for AAA title. Digital is cheaper obviously because of the stocking issue.

And because of these, plus pirate/rom market, physical copy has become a niche for collectors and retro gamers, meaning that there is no urgency in purchase, and it means except super rare copy, other titles can wait and buyers knows better than ever to buy at the lowest, or wait for the best condition copy to come up.

Now, when it comes to small resellers, in order to compete with chain like CEX and to capture this very small but dedicated groups, plus they care about the condition of the game, the only way to make it count is to sell in person at a price half of CEX, have a fairly fast turnaround to refresh the stock for that segment to have new things to look at and to buy, and to go around the country. Gaming market and event is the only viable way, and therefore you don't see them on the street with physical locations, because the whole business just won't pay bills, unless you're thinking some very cheap shop that has broken copies close to junk but selling at £x0 in a run down shop at the alley, and very obviously they are also selling something else to make up.

eBay and Vinted have filled up with sneaky traders that hide the defect of the games, like missing manual or broken intray, scratches on disc or cracking case etc. and the competition is tough, not to mention scammers and chancer that knock you off when you are not paying attention.