There do exist these things called "dwarf tomatoes". Also, a large pot and a few good cherry tomato seeds can blow away everything in a supermarket with little flavor bombs.
I have determinate dwarf tomato plants (3 feet tall max), which I grew from seed ($2.99), planted in old milk crates (free) lined with plastic from old bags (free) and filled from one huge bag of potting mix (~$20-30), and this gives me half a dozen plants that are superior to anything in a supermarket. I staked them with tree branches trimmed from my trees (free).
I have grown them in the actual ground many years, eliminating the cost of the potting mix, but after a few years, you need to let the soil lie fallow to avoid blights, so this year it's the milk crate planters.
I have determinate dwarf tomato plants (3 feet tall max), which I grew from seed ($2.99), planted in old milk crates (free) lined with plastic from old bags (free) and filled from one huge bag of potting mix (~$20-30), and this gives me half a dozen plants that are superior to anything in a supermarket. I staked them with tree branches trimmed from my trees (free).
I have grown them in the actual ground many years, eliminating the cost of the potting mix, but after a few years, you need to let the soil lie fallow to avoid blights, so this year it's the milk crate planters.