Yea, I'd try fixing it myself...that's one of the first things I learned to adjust & it really is easy. Builds confidence too for when these sort of problems reveal themselves on the road.
And no, you aren't asking too much! My LBS never charges me for that sort of tune up, they just thank me for my business. Granted, I give them a lot of business, but even when they didn't know me they'd suggest that I get myself a spare tube or patch kit and call it good. Of course they did teach me how to adjust my derailleurs and brakes...maybe that was a hint!
I'd certainly avoid the place on account of your ex-BF working there!![]()
Anne