Hi, I'm new to the Board

I am a regular commuter to school/work/girlfriends house and I average roughly 40-50 miles/week. I ride an 80's Peugeout Monaco I bought at a Thrift Store. The Frame is in perfect condition, but the some of the components are starting to show some rust/wear and tare. I was looking into converting it into a purely commuter bike and making it a single speed, and eventually by myself something nice (maybe a surly pacer) for longer distance riding.

I was wondering how much it would run at a bike shop to convert it if i buy a new crank and a freewheel. I'm a student, so money is somewhat tight. please help me out