That depends.
The port is about $2-$5, depending on the quality you're looking for.
The time of someone experienced enough to replace it without damaging the phone could run to $100-$200.
Replacing the whole board that the port is on could be cheaper, but again, it depends on what someone is going to charge you to replace it.
Is it something you can just unplug and replace by yourself, without causing a lot of damage to the phone? If I were a betting man, and not knowing a thing about you (like how many years experience you've had soldering on 0.1mm centers), I'd put a large sum of money on "no".