The tomato you pick from the plant you have grown yourself will always be fresher than one you have bought from the store and carried home. And it will be more satisfying because you have made the efffort to plant the seeds, then transplant the seedlings and finally move them either to open ground or a larger container. All this involves tasks that are second nature to someone with a green thumb, but for the less experienced the video below shows a cheap and easy method that does not even involve buying a packet of seeds.