Not really. RAM prices have plummeted recently. 8GB RAM (2x4GB) can easily be found for less than £30. 8GB DIMMs seem even cheaper than 2x4GB.
So if you were to sell it, you could possibly do it on the advantage that 'it's genuine Apple RAM!' (even though this doesn't make a blind bit of difference). Personally I'd just keep it stored for diagnostics purposes. You'd get ~£20 if lucky on eBay, and that's before the fees.