Wheelchairs: $12/day rental (no deposit) OR $10/day Length of Stay rental
Length of stay is basically a prepurchased ticket for each day you plan to rent. You take the ticket to the rental location and can save a bit of time (and $2 per day) by prepaying.
There is more information in post 2 of the disABILITIES FAQs thread. You can find that thread near the top of this board or follow the link in my signature.