would like to borrow wheelchair for 80 lb shepherd (Freshwater)

My 80 lb shepherd has a progressive paralysis and has a short time to live.
I am wondering if anyone could lend me a doggy wheelchair.
My vet feels they don't work well for larger dogs, but I would like to try it to see if it helps.
They are very expensive and dogs with this condition often don't live long.
It would be nice if our community had one we could pass around.