I think I kinda understand ...
You had wanted to buy a collector's item that was brand new. But it
turned out that the item you bought had a layer of dust and faded a
little.
Probably u did not open up the box to check before u bought it.
Later u found out that it was not up to your expectations & so
u feel unhappy.
As its inside a box, that guy may or may not have known about the
condition. If he knew about it, he would most probably have used
cloth to clean it, before giving it to u, to avoid
misunderstanding. After all, all sales men want their customers to
continue patronising their shops. He may or may not be
intentional.
U can try calling up that guy to explain, see if he can allow
return & refund, or at least some discount, because the toy's
condition was not brand new. Even if he refuses, at least u feel u
have done something about it & voiced your unhappiness instead
of keeping it inside within yourself. Perhaps he was not aware of
the problem.