If you switch the title to your name and all that BS, your time, gas money, ect... it may not be worth it.
I have a nice 93 X2 with a recent/nice turf job. If I was to sell it, I would have to have at least 750-800. I would rather have 1000 for it. I kind of need cash for a down payment, but I know if I was to sell this ski, I wouldn't find another as nice. So I will keep it.
I agree with the 300 to 700 range. Just depends on how clean it is. I pay more for unmolested, original skis than the same ski with mods. Sure I will eventually mod it myself, but I would rather pay for the piece of mind that someone hasn't tinkered the ski to death.
But also, remember there is not such thing as a get rich quick scheme!