Pools, pools, pools!
I used to build pools... "standard" 4x8m and fantasy pools up to 17m long, with jacuzzi and fountain play. Many times I worked on them directly.
I have found that the ONLY way to build a "serious", lasting concrete pool, was to use the
Shotcrete/Gunite method (check the links). Plumbing should NEVER be routed in the walls, but only go straight thru. Wiring for lamps using and upside siphon system.
Some soil will allow for the Gunite-concrete to be shot right at it, other -most- ground however, require a block retainer wall to be built first. That wall has no structural bearing at all.
Locals however, tend to build most pools using concrete blocks which are merely filled with concrete and rebar. Often, I don't even see an occasional poured concrete girt applied. This is, especially in a region with a history of seismic movement, an ill fated approach. The result is a poorly build pool, which WILL crackle here and there, the tiles or paint will lift and need attention every now and then - at BEST! Should never cost anywhere near to the prices suggested above (you can have a small house build for that price!). A properly gunited (20cm solid armored concrete walls) pool may cost you even less, for the sizes quoted.
I would like to see more fiber glass pools around here... yes, the typical ones are kind'a redneckish... but there are companies which now make high grade finished pools. Set in a good bed of sand, they may have better chances during and after earthquakes.
Liner pools... well, there's another subject many will have divided opinions about! Let me just say this: I think that if you are a handy man, liner pools using a synthetic or metal wall system, can be a great option to build your own pool virtually yourself (except for the digger!). You can get the kits on-line in the US.
6 to 10 years later, yes, you may have to replace the liner (if you could build the pool, you can do that - easy!), but keep in mind, that if you have a concrete pool, you WILL have to repaint, re-seal and often even partially re-tile after 8 to 12 years too. AND, a liner pool is the most likely one to take the abuse from seismic activity without damage.
... J-D.