Our house is 1,600 sq. ft. and we paid around $170,000 15 years ago. 3 bedroom, 2 bath.
Our mortgage payment is around $950 a month. This includes homeowners insurance.
Then there's electricity, water, trash (all one bill), gas, Internet, which adds up to around $600 or so a month.
Our HOA (grrr...) charges $180 a year. The pool is just a block from our house, which would be great if we ever used the pool.
Regular maintenance stuff probably runs a couple thousand a year, depending on what's going on.
I can't think of any other absolutely essential things.