When my patio door stopped being able to slide closed, it was hard to find anyone who could repair it. I was able to get the door off and have a look at the wheels, but it looked like at least one was broken and couldn't be attached to the door. A google search showed that Lock Surgeon could do so I called them. They told me they could send someone the next day; gave me a time window and told me it would cost $149 for the service call, and labour and parts on top of that.
The next day I got a call from Kevin right at the start of the stated time period; told me he'd be here in about 20 minutes and he arrived right on time. He got the door apart with my help and took the wheels to his supplier, which was a fair distance away - telling me he was 90% sure he could get new ones. Over an hour later he called to say he got the part, that he had to do some other work and stop for coffee then he'd be back.
We got the wheels on and it works fine now. He only charged for half an hour of his time (I was afraid he'd charge for the other business but he didn't). However the charges added up to a lot - the wheels were over $50 with their markup and he added a $25 charge for shop supplies - even though he used my silicone spray and broke my file.
All in all, I got my door repaired in a decent time so I can't complain much. I didn't have much choice - it's an oversized door and would have cost at least ten times that amount. I needed it fixed before winter came and I got that. It was just a bit pricier than I had expected - otherwise, can't complain about the service.