Developing your own roll at home with these old fashioned methods (hand loading the tank / cutting the leader / playing with chemicals in your sink / hanging the film to dry) is fun because we love film photography and everything that goes with it.
When it isn't your film you develop and you don't have that excitement building up in you from the moment you loaded the tank to the moment you can see the wet negatives on a cloth pin hanging over your bath - it is a pain in the arse of a process.
If I develop between 1-5 rolls of film, it takes me an hour every time including the cleanup etc, and then some drying time. If I was getting $15 dollars for giving up 1 hour of my free time (for 5 rolls), I wouldn't even consider. Maybe if I was 18 back in college and saving up for the Friday night in advance.
Sometimes my dad sends me 10 or so developed rolls in an envelope so I can scan it for him and despite the family connection and all, I can tell you I never once looked forward to doing it. To scan one roll takes about 3 minutes with the Pakon, then moving the folder, naming it, cutting the film and placing it in a sleeve, uploading the files to the cloud - all in all a 10 minute process per roll.
Ben
p.s. From above - if it was something that we did as a community - I develop your BnW and you do my slides - i'd be all up for it.