I don't know, if you can live off of the wife's income and have financial backing it might be worth pursuing.
I agree that you better be diverse though.
Wine, mead, pop extract. Anything else even remotely related that you could put in there.
Maybe some steady income from something not related like basic Quickie Mart inventory.
I have no idea how knowledgeable you are on brewing, but you should be able to give your customers a lot of information when they come in.
You might actually have a situation where it could work, but I have never seen any of the brew stores I've been to that were busy.
Be ready to work 70 or 80 hour weeks since you won't be able to afford to pay someone to work in there for at least a couple years if ever.
That doesn't mean it wouldn't be worth while though.
Maybe a good thing to do would be to talk to somebody with a homebrew store in at Town comparable to the size of the one you would be in.
As long as its not somebody so close that you would be competition I bet they would give you some really good ideas of cost, hours they have to work, how long till they turned a profit, and any problems that you or I might not think of.
It would help if that brew shop was in the same state that you would be in because of the differences and licensing or permit costs and problems.
Show up with a 6 pack of your favorite homebrew and just shoot the breeze.