I bought a T-shirt from the club. They were also supposed to sell lots of other Time Team stuff too, but details were always going to be anounced 'in the next issue. I seem to recall TT trowells for sale too.
Plenty of other TV programmes have cashed in on merchandising, and they haven't been slow in publishing books, so don't know why they are so reluctant.
They probably don't want a bunch of us Forum bloggers turning up on a Farm in England, dressed in TT t-shirts, complete with trowels, cameras etc pretending we're doing a TT dig As if we would!