Amazon offers Prime members the K&H Thermo-Kitty 16" Heated Cat Bed in Sage, model no. 3193, for $20.15 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping adds $7.91.) That's slightly under our mention from two weeks ago and the lowest total price we could find by $20. It's recommended for indoor use and features soft foam walls and a 4-watt dual-thermostat heating unit.