My wife and I had a fabulous wedding at the Urban Ecology Center just north of downtown www.urbanecologycenter.org. I am slightly biased because I work there, but we did look at several venues and we felt it offered the best combination of price, feel and location. Good luck!
We are gettig married at the Iron Horse Hotel in "The Yard". That is costing us $1500 for 3 hours. Which is not cheap, but was reasonable after getting quotes from places like Villa Terrace. I like this option because they have back up space for us inside (May 2012 wedding) in case weather is bad. I had really wanted to use the gazebo at Pere Marquette park, but it just seemed like a hassle to me - especially not having a back up space.
we got married outside at Pier Wisconsin in their tent. AMAZING
I had my reception at the Domes 3 years ago after they renovated. They also do wedding ceremonies as well. I like that it feels like it is outside but you don't have to worry about weather at all! I do not remember it being very expensive to rent the space because it is a county park.
We are getting married at the War Memorial. I'm not sure of the price for just a ceremony, but you should look into it, it is beautiful!
One suggestion would be having a wedding at the Milwaukee County Zoo, if it works into the downtown range that you are working with. My husband and I had our wedding reception at the Peck's welcome area, was fabulous and I would do it all over again.
We had our wedding reception 3 years ago at the Miller Room http://county.milwaukee.gov/ODonnellMillerRoom15897.htm at O'Donnell Park. I recall it being fairly cost effective. It overlooks the lake beautifully and you could have the reception out in the park (with a backup being the room). Our favorite part about the venue was that it has a covered balcony to the room, so even if it rains the party can still enjoy being outdoors.
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