Northern Tool offers the Mr. Heater 10,000 BTU Propane Radiant Wall Heater, model no. MHVFR10LP, for $99.99. Coupon code "248528" cuts it to $89.99. With free shipping, that's $10 under our mention from a week ago and the lowest total price we've seen. (It's a current low by $40.) This vent-free heater heats up to 250 square feet and features a multi-output valve, piezo ignition, and automatic low oxygen shutoff system. Deal ends October 18.