Day pass = $25
I think officially that they only admit hotel guests, but I've been there 6 or so times and no one has ever asked for a room number..
Price. 5 lounge chairs. Large hot tub. Free cans of Coke products in addition to the expected water, juices and dried fruit/nut mixture.
No shower in the steam room, No cold plunge pool.
I'm sure this was a top of the line spa when the Mirage opened way back when. It has since been surpassed by several other strip spas. It's pleasant enough and the staff is attentive and professional.