I asked myself this question this year and set about answering it. I logged all my expenses this year - $200 - and have been careful to weigh everything we have harvested and brought inside.

I have next to no good garden space without building it. My primary raised bed is built on/over a concrete pad. After that I have several DIY self watering planters (think OurEngineeredGarden blog or Earthtainer designs).

So far this season we have pulled 25.516 kg of veg, fruit, or herbs out of the garden for a price of $3.55 a pound.

I still have a lot in the yard including my experiments with a potato-tower, 12 sweet potato plants, and several butternut squash.

This year I hope to get close to parity with grocery store prices. Next year should be much more harvest for the seasonal cost as most cost this year is for container soil mix.