To pool or not to pool?

Today the forecast in Perth is for 42 degrees.   When some very nice English people went back to the UK last year, they left us with their HUGE above ground pool purchased for the duration of their nine month stay here.   While we were away our lovely house sitter went through the faff of putting it up and now we have the pleasure of resort living in our building site.  It's great.  The clothes line abutting the side  is a particularly classy touch.

On a sunday like this we are in and out of it like a fiddler's elbow.

The master plan for our house does include a pool, but the jury is still well and truly out.  The dollars required to put it in, the cost of power, chemicals etc ad infinitum, the environmental downsides are just a few of the negatives to putting in a pool.  We're told too that one the kids get to about 15 they will probably not be interested in this expensive feature, and we will spend our good money and time maintaining it.  And it's not like you can wheel it out and put it on Gumtree once the appeal fades, like some impulse buy boat or vehicle.  

Personally, I'm erring on the side of a spa.  All I really want to do is get in, get wet, sit on my backside for a while and then get out.  A big one mind you, party size.  And the thought of cranking up the heat and bubbles on a winter's evening after a run is also pretty attractive.  Any thoughts people?  Is it a bit too Kath and Kim?  In the meantime, I'm off to google spa pools....