You must have an Olympic size pool if you are budgeting $500/month for maintenance. I have a smallish one (about 30 feet by 18 ft) with a spa and we spend $100/month and that includes all the cleaning and chemicals. About twice a year we need a new filter and that doubles that month’s bill. Utility bill is virtually the same as our previous home even though the new home is about 20% larger and we didn’t have a pool in the othr home. We filter it about 5-6 hours per day. One thing I’ve loved, and it helps with the electricity bill, is that on days like today you can take a quick dip in the pool which is about 70 degrees and you feel cooled down so you don’t run the air conditioning inside. I’d say $200/month is a reasonable amount to budget. Not sure about parts going out, but our pool guy said the original owners spent quite a bit for high quality components so he didn’t think we need to do much over the 5+ years we intend to remain here. So far (3 years) so good.