2011 Z4 3.5i Invoice Price

Hi there,

I am in a process of negotiating a Z4 3.5i with premium and navigation with MSRP of $59,500 and I offered the guy $500 over invoice (his initial offer was $57,500 with 80% residual and money factor .116 with 7 deposits). He said invoice is $55,500. Is that information
accurate as edmunds.com gave me more like $51,000 for my zip code?

Any thoughts?

Thanks,

S