Looks fake as hell if you are very pale. Stupidly orange. I see people who just scream "I had a Mystic Tan!". I've had it done, looks cool on me as I'm black so it's not so dramatic for me. For very pale people, not a good look IMO.
Also, as someone who works in the field, I can tell you it can be done far cheaper if you wish. Mystic Tan is just self tanned sprayed on. Nothing more. You can get a bottle of it and just rub it on yourself. Bottle will last 5 or so applications, you'll save a ton.
The best self tanner I ever worked [in a spa with clients] with was called "SUN". Actually gave a far superior look to Mystic. St Tropez is ok too, and easier to find. For cheapness, Neutrogena [sp?] does a reasonable job and is mega cheap.