Ours is 16 x 32, with a vinyl liner and it is pretty simple to maintain. One thing to consider is that the weather makes a big difference on the upkeep. Extreme sun and rain deplete more chlorine, but not as much as frequent use. The bio load supposedly determines the most when it comes to chemical usage. Our dog loves ours more than we do lol, and it doesn't seem to hurt the levels.
Our insurance doesn't seem to be affected much, as long as we have a fence.
I'd recommend buying from a pool store the first year, as they are helpful when learning the ropes. Then you can buy the chemicals from cheaper sources on your own.