However, I have found the solution.. thanks to USDA. They have a database of market prices and you can search according the region, type of fruit or veggie, organic or not, and dates. You can also download the data as an Excel file, which will make it easy to sort. This makes me very happy! It allows me to get the most accurate price and if there's not an organic option for my region then I can get the national average.
Here's a screen shot of the database:
To test it out I had to look up my two whole weeks of harvest this year: organic broccoli for $2.99/lb, cabbage at $0.98/ lb, spinach $5.10/lb, romaine $2.99/lb. I did find a limitation to this database.. it does not have all vegetables. No turnips or rutabagas are included in the database, but it is definitely a great place to start. My veggies for 2012 so far are worth $7.57 (excluding turnips).
Can't wait until the summer bounty comes in and I can find out how much my gardening habit is worth!