Think gas mileage and then suck up to some guys that own big boats for the long range stuff. 4 strokes are the key now unless you want to pack the boat with people. There are plenty of storage options (campland by the bay) or further inland. With the economy the way it is you should be able to score a 20 foot skiff with a 4 stroker on it pretty easy. If you are good with a wrench you can get an I/O even cheaper.
Buying a house? HOAs loathe boats and trailers. Cheapest is your own house and keep it on the side.
You'll spend a couple hundred minimum if nothing is broken for maint. Realistically you better have a couple grand to play with since you will be replacing shit that gets eaten by salt. As far as brands it's kind of a Ford vs Chevy thing as besides fit and finish they are kind of all alike. Bayliner and Striper are good boats.
This is something I think you should be looking for. imo of course near SD.
2003 Triumph 210 cc for sale in South Windsor, CT: Center console - BoatTrader.com