I keep breaking spokes
I'm currently using a pretty much stock '05 Diamondback Response hardtail as my commuter. I put about 100 miles a week on it, all pavement. Two months ago I broke a spoke, so I brought it to the LBS and paid $70 to have the wheel rebuilt. I asked them if this was to be expected because it's a relatively inexpensive bike, and the mechanic assured me that the rims and hubs were fine, and now that he put on better spokes I shouldn't have a problem.
Today I broke another one. I'm 6'4", 210lbs, so I guess I'm putting a bit more strain on the bike than most, but it's not like I'm bouncing over roots and rocks and stuff. Am I being unreasonable thinking these things shouldn't break this often?
I'll be bringing it back in tomorrow and I just want to get some opinions. I don't want to blame the shop for something that's not their fault, but I just think I should get more than two months out of a $70 repair bill.