Looking for advice. I have a 1977 14x60 Sumerset houseboat with one engine. Yea I know .

First off when I am standing around the docks and the other owners are talking of 600k, million plus and other deals I am wondering how I am going to pay my $100.00 slip maintenance fee (and hoping they don't find out how poor I am and kick me out of the club). So I need to minimize costs. That being said my boat is my baby and home. I got her back after the divorce worse for wear, imagine that She has a 305 Mercruiser 228 and TRS drive. The Mercruiser was not winterized and has a busted block and exhaust. The TRS (hope I got that right) is reworked but tired.
I am thinking of taking it to a local service yard and having a new outdrive and motor installed. That will of course be expensive.
So to restate. I am looking for ways that I might minimize my costs and still have a reliable drive.