With a PHX parking ID you get a % off at the airport, you can also prepay now and get a discount. I park at the PHX Airport Hotel pay 75p/mo with covered parking. It's the only covered parking where you can get a monthly rate as a new guy (the airport isn't offering monthly rates to new parking accounts anymore.) The only caveat at the hotel is they valet the car so I feel like its courtesy to tip a buck when I pick up my car. From the hotel you can walk across the street and catch the Skytrain to the airport.