L.B.
I agree with the person who said to prioritize with fruits and vegetables. In addition, I've heard that you can judge by the water content the quantity of potential pesticides. Grapes, strawberries, cantalope, watermelon, celery, etc are mostly water and thus should be organic. Bananas are not and they also have a skin, so organic is less important. I have a list posted on my fridge that I downloaded and printed out. It's called "What you need to know about pesticides in your preschoolers food" if you wnat to google it.
As far as bargain shopping, you might consider joining a co-op. There was an article in the Dispatch a couple of weeks ago on co-ops. You may be able to look it up on line. It listed several names of local co-ops that buy canned and dry good (no fresh) through wholesalers, thus taking out the middleman (Whole Foods, Kroger,etc). The catch is that you buy in cases, not single cans. I think you place your bulk order with the coop and pick up is about once a month. I plan to do this for canned tomatoes, beans and maybe some other stuff too.
Also, many of the small, local organic farms have co-ops for the summer. If you join, you usually get a share of whatever crops are in season. I don't know if this is less costly than grocery store prices, but it is certainly more eco-friendly with lower fuel for shipping, supporting local growers, etc.
As for grocery stores, Giant Eagle carries bagged organic apples and oranges (cheaper than by the pound)but Kroger doesn't. I recently shopped at Marcs and found that they carry some organic fresh foods. I don't know how their prices compare, but it may be worth checking.
Hope this helps.
Best wishes and kudos for breastfeeding--it is oh soooo important for baby.
Laura