we got saltwater and the heater, i use the pool from April to October. I closed the pool last November and was in it on Halloween. i don't think the maintenance is that onerous. get a nice pool robot, run it once a day, you'll be fine. salt water pools are a lot less maintenance. i don't put very many chemicals in it at all and it stays really clean. run your filter correctly and you'll be fine.

in terms of cost, the size doesn't change the cost that much (a 40'x20' only cost a few thousand more than a 32'x16') but where the costs add up is all the features, i.e. how many lights, what kind of coping you want around the pool, how much concrete you want, etc etc. i don't know your price range, but that's where the costs will add up.

i would tell you that when it comes to this shit you get what you pay for. i wouldn't be shy about going a little higher on certain things, once the pool is in, it is in, and it is hard to modify after the fact.