Think about it.....
Here's a thought:
Rather than open a dedicated "gun shop" why not consider opening a "pawn shop" w/guns?
I have a casual friend who owns such a place, (he does my ffl transfer dealings for me), and I've never asked him, because it's none of my business, but I'm of the opinion he makes most of his profit on the "pawn" side, not the "gun" side of his shop.
When the economy is in the dumper (as it is now) you will get MORE business in a pawn shop, not less.. If you have an ffl license you can take in firearms on pawn, and have very little invested in them, and if they are not redeemed you can make a reasonable to quite good profit on them.
You can also special order firearms for customers, charging a reasonable profit.. My friend has done that for me several times. In fact when I get interested in a new firearm I always give him first "dibs" on finding me one at a fair price. Sometimes he can, sometimes he can't, but he'll wind up getting paid something either way.
You can become an ffl transfer dealer (as my friend is) and charge a reasonable price for simply handling the paperwork for other folks.
A word of caution however..
Another friend of mine opened a pawn/gun shop in Tampa many years ago, and he had a full time job elsewhere, so hired a fellow to run it for him when he was unable to be there himself.. This fellow became a very good friend to my buddy, and it was a bit of a surprise one morning when Ken went to the shop only to find the buddy had taken the "good stuff" (jewelry & guns mostly) and skipped town.
But if I were putting my money into a business, and it was a gun shop, or a pawn/gun shop, I'd bet the best return for my money would be the latter..
Just personal opinion, could be wrong.
Best Wishes,
Jesse