Not interested in buying them, but just to help you out with the pricing, ones in good condition typically go for around $400USD, or around $350EUR.
Anyway, these are really nice sounding headphones, good luck with the sale.
I'd love to give these a review, I have quite a bit of experience with RHA products, having reviewed the MA750, T10 and T20 and organised the Australian tours for the T10 and T20.
Here is a link to my reviews:
Good luck to everyone!