I had one. Used exclusively in salt. I added a heat exchanger, zincs, and sea strainer after the fact. It worked well. However, it still is a fresh water boat modified for salt water use - as you said.
A galvanized trailer is key.
Are you buying new or used?
I think of it as a salt water tax. If you live on calm salt water, you have no choice but to ride it. It just costs you a bit more over time to either buy a Salt Water Series boat or pay more in maintainance.