Sorry Im British/Irish so cant comment on the US residence process. I can confirm there is a wealth tax - the first 700k euro are tax exempt.
Utilities aren´t cheap. Spanish electricity prices are some fo the highest in Europe
https://www.spanishpropertyinsight.com/2016/06/06/cost-electricity-spain-high-eu-standards/
The bonus of the Andalucian climate and 50 average days of rain per year means you really only need heating Dec - Mar max. Some of the newer builds thrown up during the boom are of shocking poor quality. I´ve a friend whose house is mould ridden and freezing all winter. If you buy wisely and arent a friolero you can get by with an electric heater. Some data:
Water (for 59 days) - 285 euros July - Aug. We have a well but when it runs dry we water the garden daily (750 sqm). This was for 2386 m2 consumption
Electricity (for 59 days - 3 story house, 330 sqm, pool Dec - Jan) - 512 euros for 1,947 kilowatts consumption
Gas - we have gas central heating + cooking - 8 large bottles every winter - approx 330 euros
Fibre optic internet+phone package - approx. 200 euros per month
ABN equivalent - 1250 per year daily bin collections on street, quarterly grass cutting + weekly street cleaning
Hope that helps. Narrow down a city or town and then start to look into exact and current costs. Food across the board is ludicrously cheap, embarrassingly so. Breakfast this morning for 3 adults - 4.95 (3 coffees, mollete tostado each - that´s a long roll for the Bsas folk!)