I'm 23, but I bought my first cel when I was 19.
I agree with the other statements-- the age of
the collector doesn't really matter, as long as
they *act* mature. ^_^ Whenever someone offers to
sell a cel I'm interested in buying, I don't ask
them "How old are you?" and refuse to do business
with anyone under a certain age. Rather, I have a
feel for them by their posts--- sometimes, by the
comments on their webpage--- or, in the case of
Ebay, by what others have put in their feedback.
And it's a personal decision from there. If the
cel is really nice, but I don't trust the
individual, I'll pass, even if it's tough. And,
yes, from various conversations in the past,
there are a few isolated individuals who have
very much lost my respect.
If you happen to be a younger collector, and are
worried about the age requirement on Ebay, get a
parent or an older friend to bid for you or sell
for you. There's no shame in it, definitely...
I've sold two items to moms who were buying them
on behalf of their daughters. :o)
But as long as you have a record of being level,
being mature, and being good to work with, I
don't think anyone would have an age issue if you
wanted to strike a deal with them.