Well I do hourly labor in tiers, between roadside at $25.00 an hour, min $12.50 for the half hour if that is all it takes me. But for anything bench work like, such as re tapping for a thread repair (a royal pain in the ass which I always advise against), I go to $50.00 an hour, minimum of one hour. Usually if someone buys, and brings me the parts, on a straight yank and replace fix like this should have been with her getting a new crank arm, I'd charge the lower tier anyhow. Only people who should consider shit like a repair needing a wielding fill in or a re tap and wire insert (both being over kill 99% of the time), are like you said high end bikes, and more so high tuned bikes where replacing a major part can fuck it all up for the rider.