advice me!

Someone who is a family friend offered me a proposal regarding a co-op investment in Harbor City, Michigan. I attended one of their seminars. Recently I signed a contract on their co-op which was approved for a mortgage. I was interviewed by the co-op board. During the interview I found out there is going to be a building wide assessment which will increase monthly maintenance by $250. I was not aware of it. I changed my mind and I want to retract my offer. Can I get out of the contract?