Clipping coupons, mailing in rebates, scouting sales. Some people will go to any length to save money on purchases, and sometimes that means going to the next county or town.

The counties in the Chicago metropolitan area have varying sales taxes, and what's more, municipalities with populations of 25,000 or more or those that pass an appropriate referendum can impose their own taxes on cigarettes, liquor and general merchandise thanks to "home rule" powers.

The result is that you can save money purchasing identical items just a few feet from a county or a city line.

"We get a lot of Chicago customers," notes Paul Butler, assistant manager of the Cigarette Depot in Niles. Savvy smokers stock up at the Harlem Avenue store before returning to their Chicago homes to escape the cigarette tax of 16 cents per pack in Chicago, the only municipality that levies such a tax.

Keeping track of the sales taxes from county to county and from town to town can be mind-boggling. But a couple of rules of thumb hold true: Especially if you're a Chicago or Cook County resident, it can pay to plan everyday purchases such as gas, cigarettes and liquor with the sales tax structure in mind. It may also pay off to cross boundary lines to make big purchases, such as a car, a major appliance or a fur.

The sales tax is one of the reasons "customers from Chicago and Cook County shop here all the time," says Linda Gallo-Marx, manager of Classic Furs in Bannockburn in Lake County, where the sales tax is 6.5 percent. A customer buying a mink priced at $2,195, says Gallo-Marx, would pay $142.68 in tax at her store but would owe $192.06 if the store were in Chicago.

It's more expensive to buy cigarettes, liquor and gas in Cook County than surrounding counties because "Cook County is the only home rule county," notes Mike Klemens, spokesman for the Illinois Department of Revenue. That means the county can impose additional levies on these items.

"I try to gas up in Lake County, not Cook County," says a Highland Park resident who drives to work in Cook.

Klemens says there's a 6 cents per gallon gas tax in Cook County, and in Chicago there's a 7 cents per gallon tax on top of that.

Likewise, buying alcoholic beverages in Chicago or in Cook County means you will pay additional taxes. Taxes on general merchandise, vehicles and food and drugs also vary from county to county, but the differences of a half of a percent or so are usually not enough to warrant a change in buying habits, unless the purchase is an expensive one.

"One percent of a car purchase can be $200, and that can be a lot of money to some people," notes a Lake County car dealer who asked not to be identified. "But personally, I wouldn't buy a car in another county just to save on taxes. I'd only do it if the dealer was convenient and it would be easy to get your car serviced."

If you're a Cook County resident and live outside the City of Chicago, you can save 0.25 percent by buying your car in Du Page, where the vehicle tax is 6.75 percent, or you can save 0.5 percent by buying it in Will, where the vehicle tax is 6.5 percent.

But if you live in Chicago, here's the catch: You'll also have to pay a 1 percent "sales use" tax to the city even if you buy in a collar county but register the car in Chicago. That means that the city will collect 1 percent on top of the county tax you paid at the time of purchase-no matter where you bought the car, even in Chicago.

And Illinois residents can't cross the state border to take advantage of lower taxes when they buy their car. Lake County in Indiana has a 5 percent tax, "but we charge tax on the basis of where you live," notes Dan Keca, sales manager of River Oaks Cadillac in Hammond.

"If you're coming here from Will County, we'll charge you 6.5 percent. We have a lot of Illinois customers, but that's because our location is convenient for them."

Aside from the difference in sales tax, identical items can be priced differently in different locations-even when they're sold by the same chain, particularly grocery stores.

Explains Rich Simpson, director of public affairs for Dominick's Finer Foods: "Pricing is based on the surrounding competition, the product's wholesale cost and a store's operating expenses."

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