The Twin Cities isn't a good market for double coupons. I don't really know why that is, except to mention that the cost of doubling comes out of the retailers' pockets. Most local retailers don't offer it. Does that mean they are passing on the savings by offering everyday low prices? I don't know.

But David Livingston, a supermarket analyst from Waukesha, Wis., feels that the double coupons are really a gimmick. "Fewer markets are doing double coupons," he said. "You'll never see Target or Wal-Mart offering double coupons because they offer lower prices overall." Generally, it's the higher-priced stores offering double coupons. In a price survery by Twin Cities Consumer's Checkbook done last fall, Rainbow's prices were about two percent higher than Cub's. Some Jubilee stores, higher priced than Rainbow according to Checkbook, also offer double coupons.

What Rainbow is hoping, Livingston said, is that shoppers will come in Saturday with 10 or more coupons that they plan to double and then buy a lot of other stuff too. That's what most shoppers do. But the cheapskates who come in with their coupons, and buy only 10 items that are also on sale, are the ones who save the most.

Here are the details for Saturday's double double offer at Rainbow.

- You can double up to 10 coupons, each worth up to $1. (The typical limit is five coupons for doubling.) Coupons over $1 will not be doubled.

-You must purchase $25 before tax and coupons in one transaction to qualify.

- Coupons worth $1 or under that say "not subject to doubling" will not be doubled.

Look for Rainbow's ad on the back of Thursday's A section for additional deals, including coupons for a half galloon of milk (98 cents, Roundy's brand), a coupon for 1 dozen large eggs (78 cents, Roundy's brand), and other coupon deals for Roundy's butter, Village hearth bread and celery.