The cost would be commiserate with two things, the damage done and what car are we talking about. Does your Chevy simply need a radiator hose? under $100 bucks. Does your seven series BMW need an entirely new engine? Somewhere around 10 large. You don't provide enough detail for even a ballpark guess.

Get with your local trusted mechanic and/or dealership and find out all the small issues that could be wrong.

Just make sure your oil and coolant (water) hasn't mixed this could mean a blown head gasket or something that keeps the oil seperated from coolant (water) has gone bad...

Be cautious to driving it again make sure all fluids are full if need be you can possibly damage the engine further if you drive over heated.

It depends on what mechanic you are with. Some cheap mechanics can do a really got job, and cost a very low amount of money. But if it just started to overheat, you can just buy fluid that is just for 5-10 dollars.

Why did it over heat. Low on coolant, water pump shot, thermostat wore out and stuck, radiator plugged if older car, among other things. Could cost to less than $10.00 to over $1,000 if it should be a bad head gasket.

Overheating doesn't necessarily mean repairing