Where would one get one of these kits?  Are they expensive?

Thanks,
John Pavao

PS - My wife distincly remembers me saying, "these things taste just like
the little ones", the only time I ever tried "Portobella mushrooms", which
was months before I saw that show.  Next time I decide to blow ridiculous
money on mushrooms, I guess I'll try the Shiitake!

----------
But his point (about them being overly expensive) is probably right.  I've
thought of getting those mushroom-growing kits myself, but haven't got the
space right now.

Cheers,
Corbie