around here (east TN & ATL), the cheaper ones on CL seem to sell fast. I rarely follow up on the ones that are obviously in flip mode (not that I would never do so, because most folks seem to value their time less than I do so sometimes their flip is still worth the cash to me...a real win/win), but the cheaper $30-40-60 bikes I have called on have all sold super fast & some with the seller asking for bids or saying he's been offered more than his asking price. I get the impression it's not the same deal with mountain bikes...maybe I'm wrong there.
Also, on getting experience/skills/etc., I understand totally. I've flipped more cars than anything else & I have been exclusively my own mechanic for all things for at least the last 15 years and for most stuff 20 years. I'd rather do it myself - acquiring the tools, know-how, etc. to learn the job. The first time through, I probably break even compared to paying someone else...but from there forward I save money & after a few years into it, I had a strong enough tool collection that 99% of the problems that hit me I was prepared for. I think I'll be adding a few real 'bike' tools (plus a stand set-up...need to search archives for that!) to my collection soon, however. I wouldn't do it if I did not enjoy the process of repairing/learning/diagnosing/etc. & I usually enjoy meeting all the folks along the way in the process.