First let me say that I'm well aware that the money I'm going to spend on a safe is not enough to expect a quality unit.  I know it, and it sucks, but I have higher priorities right now...namely my daughter's tuition rent food books gas etc.  ;)

I have been researching cheap safes (~$400 mark) and I've got it narrowed down to three:

1. MESA MBF1512e $400 (http://t.homedepot.com/p/MESA-1-7-cu-ft-All-Steel-Burglary-and-Fire-Safe-with-Electronic-Lock-in-Hammered-Grey-MBF1512ECSD/203154264?quantity=1)

2. SENTRY T6-331 $300 (http://t.homedepot.com/p/SentrySafe-Large-Capacity-Security-Safe-T6-331/202930928?quantity=1)

3. STACK-ON E-4-MB-E-S $329 (http://www.stack-on.com/categories/elite-safes/products/300)

My highest concern is someone breaking into it, then fire, then flood (with fire and flood being non-concerns really).  This size is ideal; it's going in my closet bolted down and built into an existing wooden shelving unit.  Must be electronic with key override.  Will hold handguns, ammo, jewelry, any loose significant cash, and a firebox with documents.

Any opinions or other suggestions will be considered and appreciated.

Thanks!
Radar

My friend in all honestly those types of gun safes are so shitty you would be better off buying a good contractors Job Box and two quality pad locks to lock it up.
You can secure it to the floor or wall.
And truthfully it will give a similar  fire rating because those types of shitty safes really can't give you fire protection.
The stinging truth can be bitter as hell.....

From my observation, it seems one should be looking to spend around 20% of their guns' value on a safe, with a floor of $1k.  On the upper end it tapers off, depending on how much physical space is needed.  $6k can by a good tool rated safe, but you might need more than one if you have $50k+ in guns, unless they are all $3,000 rifles with $3,000 scopes, or you have a crate of .22lr.

This, a good "job box" will be better than any of those the OP listed.

The "Stack On" type "safes" can be cut open with an axe.

I wish you luck in your search.  I too have family priorities that limit my funds.  I am considering a safe from Tractor Supply.

For your consideration:

http://www.tractorsupply.com/en/store/winchesterreg%3B-gun-safe-24-gun-capacity

Sentry Home Defense Center – Model HDC11E or GunVault TacVault?

Well, I ended up buying the HOLLON B2015E from Total Security Store for $410 total (no tax, free shipping).  https://www.totalsecuritystore.com/safes/hollon/Hollon_B2015_B-Rated_Cash_Safe
After it gets bolted to the floor and my wooden shelving unit is rebuilt around the new safe, there will be no room to do much damage to it in an attempt to open it.  Of course, if someone has the time and tools...oh well.  I can replace all that's in it a few times over for less than what a "serious safe" would cost.  Maybe someday I'll have the need.

Thanks for the replies.

Radar

You said it's going in a closet. If it's a walk-in type of closet, you can cheaply add a substantial 2nd layer if security by replacing your closet door with a real door, secured in the frame with real hardware, with a decent lock.

A gun rider on your homeowner's policy, or a NRA policy would be reasonable too.