Total costs of a swimming pool is around $120 per sqf. It can be more or less depending of quality and details. This includes all systems, heating, etcetera. If you plan things to do yourself, like digging you'll have to align details with the swimming pool guy. Lot of things can be done yourself, but you need technical skills.
I think that heating with solar power will be expensive, for the heating of a pool takes quite some energy, so you'll need lots of panels. Better use in this case the same principle they use in Africa to heat water, by using a black panel through which streams the to be heated pool water.
Regarding maintenance, it's mostly about saving enough money to pay big repairs after let's say 10-15 years. Count on 5% per year of the total building costs.