So the general opinion is to add up the net value of what you intend to secure in the safe and then budget some percentage of that (10%-20%? Help me out guys!).
If you are attempting to secure a $100k machine gun or shotgun collection, you're probably checking with your insurance company and spending $10k-$20k on a safe that has some serious ratings (TL-15 or TL-30). If you're looking to secure $5k-$10k of ARs, passports, and laptops, you're probably at the upper end of residential security containers (RSC rating). If you have a few thousand in guns and papers that already fits in your existing insurance coverage you may be looking for something that's essentially a locker with a fire rating. If you've got a pistol or two and a long arm or two and just want to keep them away from kids, a trunk or locker with a padlock may suffice.
It's easier to start with a budget and go from there than it is to wade through marketing literature so they can tell you what you "need".
I have a $800 residential security container that's got a fire rating, 8 bolts, and a fancy handle on it to make it look like a safe. I have maybe (just maybe) $5k of arms in it if you counted MSRP, so not all that much. It gives me peace of mind that if some rowdy teens broke in while I was at work they'd likely be stymied. I just don't expect it to hold up for very long if 2 guys came at it with $200 worth of tools.
One other piece of advice you'll get here is anchor it, anchor it, anchor it. If it's not anchored, 2 guys and a hand truck can get it out of your place in minutes and spend time opening it elsewhere. If you only anchor it to the floor, they'll rock it free and carry it out as if it wasn't anchored at all. If you can bolt it to the floor, a rear wall, and a side wall, it just about requires more $$$ worth of tools to remove it than the contents may be worth.
