http://www.cmegroup.com/company/files/CME_Fee_Schedule.pdf Look along the left side. You will see non-member rates and other rates. Contact the CME to see which rate would apply to you if you lease. Questions regarding this schedule may be directed to the EFS Hotline at 312.648.5470
Just call the CME Membership Department directly - that's what they're there for. They'll gladly answer all your questions, quote you seat prices, and walk you through the process. Best to get answers directly from the source.