95 Sl320

Hi all -- I'm new to this forum and have a question for all of you --
what's a fair selling price for my 1995 SL320?

My car is starmarked (perfect condition) for the next 3 years and has 54K miles on it. Unfortunately, my fiancee is forcing me to sell it -- yesterday evening I placed a thread in the shopswap forum and listed the car for $37,900 (based on edmunds.com tmv minus a random discount). Much to my surprise, I received a few emails this morning from "buyer brokers" offering to purchase the car sight unseen for between $32K to $33.5K. The mercedes dealership I purchased the car from has also offered to repurchase the car for a similar price. Will I be able to get more for the car by selling it to a private party or should I just sell the car to the dealer I purchased it from? Sorry for the stupid question, but I've actually never sold a car before (I've only traded in my cars in the past).