What gun to buy
Well that depends on what you are looking for could be a shotgun, rifle, or pistol either revolver or semi auto.
I dont think you can go wrong with anything in 22lr no matter which type of gun you choose. Although you wont find them in a shotgun.
What would I buy if I had the extra money?
22 in a lever action you can find Marlins, Henrys, Brownings, and even some Winchesters in the $475 range. All of them are good guns but I'd personally choose the Henry Golden Boy for under $400 simply because I like the way they look and feel.
i also wouldnt mind having a Ruger Single Six in 22lr/22 mag. A Marlin in 357/38 would also be high on my list.
If I was looking for a high power rifle Id want one in 30-06, should be able to find new Savage for well under $475, or good used Rugers, Remingtons, as well as others in the same price range.
Shotguns Id recommend anything by Remington, Benelli, Browning or even Mossberg.
I really like 1911s but hard to find in that price range.
The extra $500 I had to spend this month was spent on ammo and high capacity mags for some guns I already own. No telling what this next election will bring us.
Like my boss always used to say "Without ammo that rifle is nothing more than a very expensive club"
Just my 2 cents worth hope it helps.