We have always gotten a locker, we put our resorts mugs in there, jackets
(depending on the weather), purchase's and a small bag with band aids,Tylenol tums, girl things, contact stuff, sun screen ect. This has saved us from going back to the resorts on several occasions.
I was there in Oct.I think it was 10.00 for a small locker and 15.00 for a large, but when you return the key you get some money back. but if you park hop which we do, you show your slip at the next park and they give you a key,this also includes the water parks.
MK - locker rental are under the railroad, where the park maps are
Epcot - on the right side in the store ( main entrance)
AK - on the left side kinda behind the store
DH- OMG I can't remember I think its on the left side.