Keep looking, you'll find something acceptable. It's not your fault that the wholesaler paid too much for it, he should know better, he's in the business. That makes me think that he doctored an invoice on the car.
There are a lot of these cars out there changing hands. There's a nice 420SEL (1987 I think) in my neighborhood for $3995.
Keep in mind that with any MB you should be prepared for at least $3k in repairs in case anything goes wrong. If you are in school and definately need reliable transportation, consider a used taurus or sable. Yes they are boring but you can get a reliable one with less than 60k for about $5k. These cars usually have no problem doing 150-200k without significant repairs.