Why would you want to rent or buy a wheelchair when the ACTS place will lend them for free? They have a wide variety of types and sizes of wheelchairs available, and unless you need a highly specialized version of one, it's so worth it to use their services.
We donated a lot of items to them when my mother passed away, and while she was alive we "borrowed" a few things from them that were a great help to us. Of course, they were returned to ACTS when we/she no longer needed them.
I just can't say enough good things about this group.