While there is debate on whether organic food is safer, more nutritious, or tastes better than conventionally grown products, if your primary reason for buying organic is that you want to do your part to lessen the impact farming has on the environment, you’re doing the right thing. Much research has found the practices used by organic farming cause less harm to the environment than non-organic practices (although things aren’t as clear on organic meat production).

But buying organic means paying a lot more for food. The market basket we used to shop local grocery chains and stores included 25 fresh produce and 33 meat and dairy products. When we survey stores for their prices for produce, meat, and many of our dairy items at grocery stores, we seek the lowest-priced items available, which often are non-organic products. But when we looked for organic-only options, we found striking price differences: Overall, organic products cost 69 percent more than their non-organic counterparts.

The figure below indicates how the Bay Area chains and stores we surveyed compare for their prices for organic produce, meat, and dairy products. The $81 score in the produce column for Sprouts Farmers Market means that its prices at the store we surveyed for organic produce were about 19 percent cheaper than the average prices for the comparable organic produce items at all stores we surveyed. The $108 score for Whole Foods means that its prices for organic produce were about eight percent higher than average.

As you can see, the organic-price penalty is bigger at some stores than at others. For produce, Sprouts Farmers Market and Trader Joe’s, which offered low prices for non-organic items, also offered low prices for organic options. Raley’s and Berkeley Bowl’s prices for organic produce were also quite a bit lower than what we found at many other local chains. Raley’s, Sprouts, and Trader Joe’s (but not Berkeley Bowl) also offered low prices for organic meat and dairy products.

Keep in mind that some companies clearly have higher buying standards than others, as indicated by the huge chain-to-chain differences we found by surveying area grocery shoppers. When comparing prices vs. quality, Berkeley Bowl stands out for produce and organic produce: Its surveyed customers gave it very high marks for the quality of its produce, and its prices were among the lowest. On the other hand, Whole Foods, which also gets high produce quality ratings from its customers, offered higher-than-average prices for organic produce and only slightly lower-than-average prices for organic meat and dairy.

Some stores carried too few organic items for us to include them in our comparisons. Many of the area’s price leaders, including FoodsCo, Grocery Outlet, Smart & Final, Target, Walmart, and WinCo offered very few organic alternatives at the locations we shopped—too few to include in our comparisons of organic prices.

Know that while buying and eating organic likely does lessen the impact of agriculture on the environment, the most environmentally friendly approach is probably to eat less meat (or none); minimize purchases of highly processed and packaged food; as much as possible eat what’s in season; and whenever possible buy products grown or raised locally that didn’t have to be shipped a long distance.

Want info on locally grown food sources? The nonprofit LocalHarvest.org offers a fantastic online database of searchable listings of farmers’ markets, CSAs, farm stands, groceries, and restaurants.