Just saw this section, but thought I would add my two cents since I have been growing tomatoes for about six years from plants.

My best find for the past two years has been the garden fair at the Garfield Conservatory in late April. Nicholas is there and they sell their tomatoe plants for 1.00 each of six for 5.00. They are obviously smaller than the ones they sell later in the year, but a great deal for amazing variety.

Last year, a vendor sold fuzzy peach cherry tomatoes that were simply amazing, but I could not find them this year. The Oak Park Farmer's Market is also a great source for seedlings.