Don't just buy organic. Buy local. Yes, organic foods are better for the environment in terms of their production, but if you are buying organic blueberries that are shipped in from Chile, are you really doing a lot of good?
If you want to buy organic foods, but can't afford the extra cost, choose the foods that are typically higher in pesticides to buy organic. These include: apples, bell peppers, celery, cherries, grapes, peaches, pears, potatoes, raspberries, spinach, and strawberries.