Watch craigslist for safes! If you're lucky you might pick up one from a business that's failing.
I failed to grab a TL30 that was the right size for $750!
Buy larger than what you think that you will need, Photos, cash, birthcertificates,negatives watches,dvds that you don't need out,ammo,jewlery,pistols,optics,mags,slhotguns,rif les, & cameras.
When I bought my safe I was "All I need is 1 rifle,1pistol & 1 shotgun add 4 other rifles and 20 mags and other items and there's not much air in there.
Do take some time and look at
Gun Safes : Fire Safe Manufacturer : Sturdy Gun Safe he's got some great videos that will make you want one of his safes. I really want
Model 3627-6 : Gun Safes : Fire Safe : Sturdy Safe with his fire protection and some other options