I think a fair starting bid would be 2 XMR. Otherwise you are just wasting everyone's time.
I'll offer 5 XMR, (Unless Hhampuz is really serious)
As Cryptonic21 told Vigens and myself via PM a while back was this:
It's the most rare cryptonic monero coin in existance from the very first batch of pure silver monero coins ever minted.
That said, I think it's worth a lot more than even 10 XMR right now. People all have opinions, but these are no longer being made, and rarely sold either, so finding an Orange/pure silver XMR coin, especially this unique is NOT going to be easy down the road.
Cheers & keep the hate to yourself please!