Home Depot has the Gorilla Ladders 20 inch Work Platform for $49.88 (regular price $74.97 - only a 33% savings this year) as part of their Black Friday Savings. The load capacity is 300 lb., and it folds to 3.25 in. for easy storage.

I had the Werner work platform, but now have 2 Gorilla platforms, and the Werner is in my mother-in-laws garage for use there.