To answer your
question, the main question I would ask is "where would
the benefits of the sale go" ?
I hope, benefit will go for the good of Wikipedia :), but it will be
not monetary.
I plan this so: several wiki-users in Moscow will have a whip-round
and order in printing office tee-shirts for themselves + a few as
presents for admins (most active participants) and/or as prizes in
contests. (If we shall agree upon it)
Also, I think, some people will want to print the same tee-shirts for
themselves in other cities.
The net profits from this exercise are bound to be very small. If they
can be applied to help develop a Russian national organization that's fine.
Ec