Pricing is really all over the place. And a rig that is in parts is a lot less attractive than even a roller that doesn't run. You would need to post pics and a list of what's what and what new parts come with it and what may be missing. I have seen projects go for good money, but they tend to be at least partially put back together and include a lot of new parts. If its just a pile of rusty parts it is not worth as much as a put together rusty bronco!
With all that said there is a buyer for everything. Good luck with the sale!