Tomatoes: Transplants vs. Seeds

Although tomatoes are easy to start from seeds, I purchased several different varieties of heirloom tomato transplants from Home Depot.  They were selling them for $3.48 each, and they came in 5" peat pots.  So why did I purchase transplants if tomatoes are so easy to grow from seeds?

1. Early Harvesting Time.  Transplants have been started indoors from seeds several weeks prior to the spring planting season.  This means my newly purchased tomato transplants will set fruit much earlier than a tomato plant started from seed during the normal planting season.  It will continue to set fruit until the first frost in fall.  
2. Cheaper for People with Limited Gardening Space.  Unless you harvest seeds from an heirloom tomato from the market or can get them on the cheap, it may be slightly more expensive to buy a standard pack of seeds.  For example, Burpee is selling a packet of 50 Black Krim seeds for $3.95.  That packet of seeds cost $0.47 more than a transplant.
3. Limited Space.  I do not need 50 Black Krim tomato plants.  I only want one for now.  I do not have the space for it, and I am more interested in having a variety of plants in my garden.  
4. Free Future Seeds.  I can still easily save seeds from the tomatoes my transplants will produce this year, and start my own transplants early next year.