What should I pay for a 2003 C230?

Hi, my name is Sommer and I live in Gainesville, Florida. I have been researching this car since last year with plans to buy one this year. Well the time has finally come and I am excited to say the least. I am currently driving a 1993 ford explorer and it is time for a Benz. I have gathered a lot of information mainly off of the Internet. Edmunds.com provided me with invoice prices and MSRP prices. I am looking for a black C230 with the C5 package and auto transmission. The total invoice price for a 2002 C230 w/options is $27,659.00 and the MSRP is $29, 690.00. What would be a fair price to pay for this vehicle? I was able to get one dealer in Miami to say he would sell me the car $100 over dealer invoice and would provide me with a copy of the invoice. Does anyone think I can do any better. I am willing to bargain, and actually enjoy it. I am the one spending the money and feel I have the upper hand. Can anyone provide me with any tips or suggestions that helped them when they were shopping for their MB? Any help is greatly appreciated :!:

Sincerely,
Sommer