When it pays to buy organic

Trying to decide when to spend the extra money on organic or not? This may be a helpful guide for you:

The least-contaminated produce tends to have protective peels, like bananas, citrus fruits, pineapples, mangoes, onions, eggplants and avocados. Because they are naturally encased, these do not need to be organic.

However, the following items SHOULD be purchased organic:
peaches
apples
sweet bell peppers
celery
nectarines
strawberries
cherries
lettuce
grapes (imported)
pears
spinach
potatoes