My favorite denim repair shop, Denim Therapy, is having a sale for the next three weeks. Get 15% off any repair order with the checkout code SUMMER16. To redeem the offer, you’ll have to send in your jeans for a price quote. Once they estimate how much your job will cost, you can pay for the order online with the promotion. Note, the code has to be redeemed by July 14th.
From past experience, I find they charge about $25 for chainstitch hems, $25-30 for your average crotch repair, and $8 for stretched out buttonholes. Obviously, prices will vary depending on the extent of the job and you’ll want to factor in a little extra for shipping (about $15 each way). Prices aren’t cheap, but their work is very good.
For a more complete review of Denim Therapy’s services, see Heddels. The company also has a fun video showing their repair process.