I think we are living in free economy, right?
Once you sold your item to somebody, you have no
right to say anything about it because you are
not already an owner of the item.

And I know some collectors in USA bought a certain
anime cel at my friend's site, and he posted it on
ebay,then it was won at very high price.
Actually he got benefit, but we don't say
anything about it because the item was already
his property.
Can you say to him "Don't sell it" or "Don't
sell it at the price over the price I sold you"?
If you really want to sell it to the real fan,
you should sell it to him directly and should not
post it on ebay.

Anyway I don't talk about it anymore.