Before you do ANYTHING, get an appraisal on it from a local dealer, or at least someone who sells similar vehicles. :sour:
If you do decide to accept it as a partial trade & aren't really interested in using/keeping it yourself, then unless you want to risk maybe buying into a world of difficulties & time-wasters, you really want to have someone ready to take it off your hands for cash right away, & that's where getting it appraised by a professional or at least a retail outlet comes in handy. With any luck, you can just hand it straight over & pick up your cash. If you can't do that, be prepared for a long wait before you see any $$ for it - after all, if it's worth that or more & was easy to sell, then why hasn't the previous owner sold it already & so have the cash on hand to buy your Spyder outright?? :dontknow:
Maybe you'd be better off to say 'when you've sold the toyhauler & have the $$ in hand, come see me about buying my Spyder - first in with the full amount in cash gets the F3!' And who knows, they might even end up selling it for more than they actually need to buy your F3, in which case that's their good luck..... or not!! Sure, in this case any profit is rightly theirs, but equally any risk is theirs, not yours, which is exactly as it should be!! But putting it bluntly, it's the only way to be certain that you wont be left out of pocket &/or sitting on a lemon that you can't shift!! :thumbup: