What's the going rate? Generally my area A&P's charge $50/hr.
Where I live, if it's at an FBO, what with overhead and all, around $85 per hour. If you can find a mechanic who wants to work at your hangar, using your tools, maybe you could find one for $50 per hour.
At my airport, major repairs are not supposed to be performed in hangars, and mechanics are not allowed to run businesses out of their hangars.
The mythical low-cost mechanic who is willing to spend his time busting his knuckles on your airplane for a six pack of beer does not exist where I live.