Lowe's has a Sentry safe for about $108 that is .8 cu ft.It is fire and water proof to certain standards.Importantly,it is still both after being bolted down;many fire/water proof safes are not. There is a combi lock with a key back up..another detail is the lock is metal,thus won't melt while in the fire.I spent about a month reading specs and reviews before choosing this one.There is a 1.03 cu ft model for about $50 more.
Be careful - that's one of the models I was talking about that has high-moisture insulation to provide the fire protection. From the owners' manual:
"DO NOT store delicate items directly in your safe. SentrySafe products which offer fire protection have a proprietary insulation that has a high moisture content. In addition the SentrySafe advanced safes close airtight to offer water resistance, which may also cause moisture to accumulate inside your safe.
The desiccant packet included in your safe during shipment should be left in your safe. DO NOT DISCARD IT. It is intended to help absorb moisture which may accumulate inside your safe. Please open your unit periodically to avoid moisture accumulation.
￼￼￼￼￼￼￼￼￼￼￼￼If you choose to store delicate items such as jewelry with working parts, watches, stamps, or photos in your safe, we recommend putting them in an air-tight container, prior to placing them in the safe for storage.
NOTE: Sentry Group will not be responsible for any damage or loss of items placed in the unit due to moisture."
I left a nickled revolver in one of the Sentrysafes for two years while I was stationed in California, and when I came back it was a rusted mess.