I just got back from Umrah and I have seen a lot of people using the wheel chairs. Our hotel gives us one to use during the stay as i have a 2 year old with me.
But for the first day we forgt the wheel chair in the room and when we were going for Saee, there were a lot of people who you could rent the wheel cair from. for saee they were asking 100 Riyal…we found one who agress on 50 Riyal. There were people using them during tawaaaf as well and that was not a problem at all.