Tinting cost me 225 for 5 windows on my 95 GL. Just don't do it yourself unless you really know what you're doing. It looks easy, but its not, and it will look crappy. Also, I would highly recommend staying within the legal tinting regulations for your state. Cops will pull you over and give you a nice ticket if it's too dark, and you will have to take it off unless you want to pay the ticket.
