A new radiator hose can cost from as low as $10.00 to as high as $40.00 to $50.00 depending on make and model of vehicle.
If you can just drain down the coolant yourself and then remove a hose and replace it with a new one then you can do it with the cost of the part.
It's pretty simple to replace a radiator hose in most cases unless your vehicle has the radiator hose buried underneath a bunch of other stuff.
If you have a shop replace the radiator hose it could cost from $50.00 to $100.00 or even $200.00 depending on the cost of the radiator hose and whether or not you need both radiator hoses replaced.
Auto shops and dealers will mark up their parts to make a good profit.
A good local mechanic can easily replace a radiator hose cheaper than a dealership can.