The message
from Martin Brown contains these words:

/snip/
Growing them in summer in a greenhouse isn't all that cost effective
either. You get plenty of tomatoes, but at exactly the same time as the
price falls through the floor. Unusual cultivars are worthwhile.

But you can grow some of the more usual ones which are difficult to find
in shops, if not impossible.

Customer: "What variety are they?"

Greengrocer: "Dutch, luv."

I used to grow Alicante, Shirley and Ailsa Craig on a small commercial
scale. They didn't crop as heavily as Moneymaker, but they didn't taste
of damp rags. I never had enough to keep the farm gate customers
completely satisfied.

--
Rusty Hinge
horrid·squeak&zetnet·co·uk
http://www.users.zetnet.co.uk/hi-fi/tqt.htm