I do love plants from Bonnie Plants. They almost always grow well, and they look so healthy and happy in this picture. The only problem with the photograph is that I took it yesterday, in early March.
Temperatures below 40 degrees F damage tomato plants, and by my calculations, we have another six weeks or so of nights when the temperatures might dip below 40, and about that same amount of time when frost might occur and kill the plants. The average date of the last spring frost around Columbia is April 16, and in recent years we had frosts in late April. I have learned this lesson the hard way, as I described in this post.
Don't buy tomato plants now unless you plan to keep them indoors under grow lights, which I do not recommend. If you were able to keep plants as large as the ones on the top row inside, they would be enormous by the time you could plant them outside, and because of stress, they would not produce as well as those planted outside at the proper time.
If you have a greenhouse and can be sure to keep the plants warm enough to avoid damage, then buy the tomatoes and enjoy eating fresh tomatoes before your neighbors. Greenhouse owners, I imagine, probably start their tomatoes from seed anyway, though.
I did not buy tomatoes yesterday, but I did buy some of these lovely broccoli, cabbage, and Brussels Sprouts transplants pictured below. Bonnie Plants also has lovely herbs, lettuces, and many other vegetables that it is time to plant outside. They even have baby asparagus and strawberry plants. So succumb to the beautiful plants in the garden center and buy some, just don't buy the tomatoes until late April. It is, however, the perfect time to start tomatoes from seed inside the house. Mine are busy germinating (I hope) under my grow lights upstairs.