"Safes" (RSC, Residential Security Containers, to be entirely accurate) have gotten a bit more spendy in the last few decades. This tracks reasonably well with inflation, though.
Right now, to stay under $1000, you are limited to the locking cabinets/lockers, and those get really competitive in the $350-500 price range. The heavier--literally, as in over 500#--RSC are all closer to $2000 as a ballpark, budgeting, figure.
Which is some cash to lay out.
But, if you have ten $500 firearms, you are spending 2 grand to protect 5 grand.
The heavier RSC offer more fire protection, but the risk of fire versus housebreaking varies widely by location. That's an individual assessment. Maybe the risk of fire is worth and extra $500 to go from 1200º to 1800º of "protection"--but, that's down to what the response time of the FD and how frequently houses burn down in your location.
It's really very individual. Kind of like how "armoring" a closet or spare room might be better. Maybe. Perhaps. YMMV