Originally Posted by StephenH

For the "walking around" part, try mountain bike pedals and shoes.
For the Size 15/low cost, try Nashbar. They don't have every show in that size, but I have bought size 50 shoes there before. Sometimes they have sales on big/small stuff, they'll have sales on out-of-season stuff.
(15 sounds bigger than 49, by the way, don't think I've ever owned a size 15 street shoe, but wear size 49 bike shoes).