Moving cost are normally around $50 per mile so it's much cheaper finding one near by. Set up cost will depend on your setup cables or mud poles rough water or cove location etc. I went through this 3 or 4 years ago luckily my neighbor 3 houses down was upgrading to a new very large dock and I bought theirs. Permits require modification permit through ameren around $500 give or take a little. The moving set up and permits can add up fast adding over a thousand plus to the cost. My advice would be sell your dock first because where are you going to put it when the new dock comes? Some dock companies will take it as trade towards a new one if it's nice. It was a pain changing docks but once it's all done it is nice. One more thing when looking at used docks make sure electrical is up to code or how you want it. My dock was a bigger pain because the knoband tube running down to the dock had to be redone. The electrical on the dock had to be redone I bought a used dock locker had it added to the side and needed a boat lift so all said and done the used dock I paid 5k for with moving setup permits adding the locker and redoing electrical cost 20k.