We've decided to get married here at home in the Northwest suburbs and I need a place to have our ceremony and I'd prefer it to be on the low cost side.  Any ideas?  Parks with a pretty gazebo?  Little chapels?

check out your local park districts. They usually have cool places for dirt cheap.

In Glenview IL there is a cute chapel called the Schram Memorial Chapel.  Also in The Grove in Glenview there is a cool outdoor gazebo and woodesy area that they do weddings and receptions. For The Grove, you would have to caterer in your own food, but for a small wedding the place is awesome looking.

Ditto kdh about the local park districts. 

If you need a place for both ceremony and reception, Country Squire in Grayslake has unbeatable prices, and 12 acres of land for photographs, along with a gazebo for outdoor ceremonies.  They've gotten mixed reviews, so I'm not sure how I feel about that, but definitely worth checking out...  Also, Byron Colby Barn also has space for an outdoor ceremony, and their preferred caterers range in price starting at $19.95 a person!