A better solution would be for the person to get their FFL and begin a small home based business handling transfers at a low fee, locating guns for friends and others, providing outstanding customer service until they build up some clients. They could also spend time buying and selling from gun shows, local stuff, and the national gun auction houses.
A man I know locally started out this way, when he retired, as more of a hobby really, and a way to buy/sell/trade on his own license. He had a very nice little shop in his back yard (made out of a yard building, actually, but a very nice setup...heat, a/c, etc.) He didn't keep inventory on hand, and dealt via the internet, local contacts, etc. He did stock some ammo, parts, etc, but very few guns on hand.
Recently, he decided to open an actual gun shop, and he is regretting that. He told me yesterday that when his lease is up in November, he is either going back to his internet only business from his home, or go out of business all together, since he's not making enough money to pay his rent on the shop.
The reasons: for one thing, his shop is in a small town, so there isn't a lot of walk-in traffic. His inventory is low, so when someone does come in, there isn't a lot to choose from. He said that it's tough for him to get guns from the distributors, since they sell first to the bigger gun shops, and in some cases, won't sell at all unless they are an established stocking dealer for the brand (which requires a certain volume of purchases and sales.) When he does get a gun in to sell, it usually sells very quickly, as soon as he puts the word out to his contacts...but like he was telling me yesterday, even that is iffy. He finally got in two Shields and two Glock 19s, based on expressed interest from his customers, and the Shields sold the same day he got them. The Glocks have been sitting there (his customers bought elsewhere, while waiting on him) for a while now. His prices are competitive, too, at least with other shops I have seen around here.
The other factor is that, besides being in a small town, his primary interest and client base is cowboy action shooting. Most walk-in traffic isn't into cowboy action shooting, or at most they may be looking for ammo. The only shops in the area (Dallas) that seem to be thriving are the really big, high inventory/high volume shops.
My wife has frequently encouraged me to open a gun shop. If I won the lottery, I would probably buy one, and run it as a hobby. If I wanted to make a living, and needed the income, I wouldn't.