What does it cost to keep a horse? ?

I have So many questions about keeping a horse. Basically, how much is the overall bill? Specifically, how much is a bale of hay (idk about sizes I would think a regular one)? How many bales of hay does a horse eat in a year? What does an spring/fall vet check up cost? How much does it cost to shoe, and how much? How many mpg while pulling a trailor? Thanks! If you have any answers to these questions please help me.