If it's a switch, you're in luck although i have always had a hard time taking the switches out (if someone knows a trick, fill me in).
If it's a coin mech, you are talking maybe $75, but it sounds like it could possibly be the main board or monetary board if the switch isn't the problem. The boards can cost anywhere from $50 to a few hundred.
If this is solely for where you work and not for a vending business, then fixing the machine is the best thing to do. If you were a vendor, then it depends on whether it's just a switch or something more.