Amazon offers Prime members the SentrySafe .66 Cubic Foot Waterproof Fire Chest, model no. H0100, for $29.85 with free shipping. (Non-members can spend $35 to bag free shipping; otherwise, it adds $14.05. Walmart charges a few cents more with free in-store pickup.) That's the lowest total price we could find by $8. It features fire protection for at least 30 minutes at up to 1,550 degrees and is ETL-verified waterproof.