996 Turbo Twist knockoffs?

[87911jon]

I've done a bunch of searching and haven't found a whole lot. I'm curious what the 996 community thinks a set of 18x10 and 18x8s are worth. Rims only, they're in excellent shape and include the Porsche center caps. Thinking about buying them from a good friend, but don't want to make sure I don't lowball him. Thanks