Yikes, just got a bid from the local marina for $4100 complete which seems pretty expensive.
"Pretty expensive" is a major understatement! For that price I'd fly up there and install it myself AND also pay the certified marine electrician in Detroit that I happen to know to do the wiring (which, btw, is the critical part of any electric toilet installation)!
Seriously...If you'd like to send me a PM, I'll give you his contact info. I've done some work with him on a boat that needs a new sanitation system...he won't gouge you. And I'll do a little research to find the retailer who has the toilet you want for the best price.
--Peggie