I have the 2 band version of your 3 band and was looking to sell it a bit back. At the time £300 seemed to be about right for a ph 2 band in good working order. £350 for a really nice one with a few bits with it. I payed £300 for mine off a mate but then had to buy a mold ect. Dont know if the 3 bands fetch more or not.
I took it for one last go and decided to keep it, figured i couldnt replace it with anything more intresting for that sort of money.
Will ask around at our club if anyones after one.
Best Wishes, Tim