Lots of variables there that can affect the price. Are you wanting to run a single 220V circuit to the garage or install a sub-panel so that you can have multiple circuits? What kind of amperage? Do you plan on doing any of the work yourself or will an electrician being doing it all? Is there an open spot in your main panel for a double pole breaker or does the main panel have to be upgraded?
Installing a sub-panel would be the most versatile if there is no existing power in the garage. If you already have power out there and just need to add a 220V circuit for a welder or air compressor or something like that, it would cost a lot less. If power is already at your garage, how is it getting there? (i.e. is it wires strung overhead or is there buried conduit).
If you have an electrician do it, they are most likely going to want to bury the wire and run it through conduit. If you already have existing conduit that is large enough to add more wires, it will cut down significantly on the cost. If you don't have a buried conduit already, can you dig the trench yourself and does it run under concrete or through very rocky ground?
If you want run the wire underground through a conduit and you are within a city, keep in mind that you'll need a permit and the required inspections. If an electrician does it, they should take care of all of that. If you dig the trench yourself, I believe the current code requires that the top of the buried conduit be at least 18" below the surface of the ground - direct burial wire must be at least 24" deep. If you are outside of a city and not subject to inspections, you could get away with less since there would be not permit or inspection, although it won't be to code. I would still do it the right way even if you are outside of a city and not subject to inspections.
The amperage of the circuit will have a big influence in the cost. If you are running a single circuit, I would probably run a 50A line, which means 6AWG wire. If you want to put in a sub-panel, you'll probably want to go with 100A, which means more $$ for wire.
My garage is attached to the house so I didn't have to worry about trenches or anything. I ran a conduit through my basement ceiling out to the garage and put a 50A range outlet in that serves my compressor or my powercoating oven. My run is a bit longer - probably a good 60 feet. I spent about $300 on just the wire. By the time you add in a breaker, junction boxes, etc., I was probably right at $500 and I did everything myself.
For you, I think the biggest factor will be the labor involved with getting the wire to the garage. Not counting any digging, a good electrician should be able to complete a straightforward circuit addition in a few hours. Materials shouldn't be more than a few hundred dollars for a short run on a 50A or less circuit. I don't know what the going rate for an electrician is these days, but I bet you can count on around $100 an hour. If there is an existing conduit and new wires can be pulled through, you are probably in the $500-$600 range for a single circuit. If you need a trench and new conduit installed, that figure could easily double. Dig the trench yourself and you'll cut several hundred dollars off the bill - just make sure you get it deep enough. I don't think there is any other "legal" way of running wiring out to the garage - underground is the best way to go.