My big city (500,000) has only one true bike shop. There is a smaller place, but he doesn't have much in stock. There are many shops in other nearby cities, but that would mean a 15-20 minute drive or more. There are also none of the co-ops where you can get DIY help. I don't have a workshop or garage anymore(divorce). I work in a big city with many bike shops, but there aren't any shops within 15-20 minute drive of there either.
I decided recently I wanted a compact double, for my older bike with a 7 speed drive train. I found the part online cheap. So instead of taking it to my local shop, I researched some alternatives. There was a guy on CL advertising mobile repairs. I got an estimate from him - $80, and a couple of days without the bike. Thought that was about what I'd get charged at the LBS, and a similar timeline. Finally I found another guy, one man operation working out of his house.
Contacted him, he said it would be about an hour, and his rate was $35. I came by on a Saturday morning and he wasn't busy. I was impressed when I got to his shop, which was part of his basement, well laid out, organized., and a steel ramp to get bikes down the stairs. Turns out he used to own a bike shop, went into another business, and retired. He installed the crank quickly enough, but then took his time adjusting the derailleur, and had to move the front derailleur down. He was happy to have me there with him, explained everything he did, told me what to check for in case my crank needed tightening after being ridden hard.
He did the job while I waited, was friendly, knowledgeable, great to work with. That is someone I will do business with again. I will get my parts where I can.