I'm based in Dubai UAE.
I have an original Lotus Cars box / packing material for a hardtop so that helps. It will be fairly light, so I dont think freight will be that much, but would need an address to confirm.
Price, the going rate I guess, I'd need to check what recent ones went for.
I know from personal experience that the size, rather than weight is an issue. Make sure you a get a quote based on the actual dimensions of the box or you may get an unpleasant back charge. I saved 100 bucks by having an ebay seller cut down the box size slightly, while still offering good protection. I think domestically it is 90 inches total dimension or something that makes the difference.
Weight, not size appears to be the key factor with the freight service I've always found good (UAE Post Office)
Estimate : UAE to USA, 20 KG, 150 X 150 X 50 CM, 2-8 working days, tracked service = Approx US$300
These show up so seldom, as in almost never, that there really isn't a 'market' price. It boils down to what seller is willing to take for it and how badly the buyer wants it.
If you're stuck on OEM, that's a very small pool. Look around at aftermarket alternatives. I had a carbon fiber one, that I had painted body color (Canyon Red), which once painted was virtually indistinguishable from OEM.
You may want to try contacting Shinoo regarding his recent post: Parting Out: '08 S240 Exige
You may have to be patient though, I emailed him about a week ago with interest in some items off this car and haven't heard back from him as of yet. I suspect the coronavirus lockdown of California may be the culprit.