I concidered it on my car. I had brand new green carpet and paid $110 for it. I then decided I'd going black as well. Best I can figure, it will take at least 2 cans of die at 13 bucks each after tax. I bought new carpet at the Indy swap meet for 80 bucks and sold my new/old green carpet for 40 bucks. Got really upside down on the whole thing. I'm dying my new $600 green seats black and the die works pretty good... Even if it takes 3 cans, I'd go for it.
BTW, I'm using SEM Colorcoat. People recommended the "Landau Black" color, becauce it closely matches the original. It's easy to apply on vinyl.