Amazon offers the Intex Inflatable Pull-Out Chair & Twin Bed Mattress Sleeper for $18.61. Plus, Prime members get free shipping. That's $4 under our September mention and the lowest total price we could find by $8. It features a waterproof flocked top and sides, 15 gauge vinyl bottom, and 220-lb. weight capacity.

Update: The price has dropped to $17.18.