I may have a minority opinion around here, but as a long-time pin trader, if you're buying pins just to trade, I wouldn't worry about it. You won't be able to tell the difference, the CMs trading with you don't care, and it's all just for fun. Now, if you're buying to collect -- seriously collect, and not just to look back and reminisce -- you
might have to be more careful. The
only pins you don't want are the
plastic pins and one that are
marked "Sedesma" on the back.
You might have trouble trading
those at the parks. I personally
wouldn't buy pins from someone
on ebay that doesn't post a picture
of the exact pins you'll buy (usually
called "grab bag" pins), because
then you have no idea. But I buy
and sell pins on ebay for my
personal use (nothing listed right
now -- got kind of burned out on
posting and not having them
purchased), and always post a
picture and only buy if I can see
exactly the pins I'm getting. When
you trade a pin, the CMs don't
really look at it and decide if they
can take it -- they don't own the
pins they're trading, and they're not
trading for their own personal
collection.