C320 trade to SLK320

am thinking of trading my 2001 c320 for a new slk 320 (and paying difference)<br> my c320 has many options,bose stereo,cd,sunroof,auto climate control,michelin pilot rubber,brabus sport grill and exhaust tips,only 6700kms ,stored in winter, and in showroom condition,cost new $56850 <br> Canadian dollars, i figure a fair difference to pay would be around 15g,am i in the correct range? the dealer in Calgary says 'Just over $22000 Cdn', does not seem right to me.<br> all usefull infomation on this a<br> ppreciated.