I bought an original, near perfect JBL D130 on eBay for $120-130 (can't recall precisely). So that should give you a typical range, though up to $150 or so would be the upper end of typical.
I notice that most of the completed listing fall around $100-120/ea for the D120F. Then there's another batch that are closer to $200/ea, and I can't tell exactly why.
There's an odd miss-mash of values for original cone vs recones on eBay. Don't know why as typically good, original cones fetch more.
When I got my JBL, the seller did some very awesome packaging: He had a plywood "baffleboard" with mounting screws installed, to which the speaker was bolted. No hole cut in the board, so the cone & dome were protected. Then that was lowered into a cardboard box with the exact same internal length/width dimensions as the board. I don't recall if he double-boxed, but might have.
If you sell on eBay, I'd encourage you to take your photos, then box the thing however you'll actually ship it and get accurate size/weight info. Otherwise, there's a good chance eBay will underestimate your shipping costs. Come to think of it, a local sale via craigslist might be a better move...
I'd be interested, but have too many partially-complete projects right now to take on anything new.
