Of course you could. The big question is, do you have room in the bow to do so. Or are you going for a pod type that bolts on. You will need to enlarge your house battery bank or add a dedicated battery to power the thruster.
Most boats in your size don't need one. Yes, they are very helpful and I have one myself. But my boat is bigger. More freeboard meaning my cabin catches the wind and and I have a single engine too.
Now you could go with a twin engine boat. With one engine in REV and the other in FOR you can turn on a dime. Just a thought?
I just got two prices for my boat, both around $10k. It is a different boat, but not so different that the price is not likely close, or in the range at least. I am in the north, so locality might affect price.
On a small boat as yours, I would not think it would be that high. If it was me I would ask, "how much if I do the wiring?" They may or may not like that. But the wiring is the easy part of all this. Which thruster are you installing?
On the other hand, you may want to go with a bigger boat in a year or two. If so, I would save the money and go with twin engines.