You guys are funny, soaking the MAF, cotton swabs, haha! Go to Pep Boys or Autozone, get some CRC MAF Sensor cleaner spray, $6 for a huge can. Take apart the MAF (some sensors have a insert that unscrews from the body using security torx screws, some don't). Spray the heck out of it, specially the gold colored wire. Don't touch it, residue from your skin or cotton swab is enough to contaminate it. Also look for oil in the intake tube, even putting in a new one will not help if there's a source of contamination in the intake. Check your air filter, a bad airfilter is one reason MAF's fail.
If you want a new one, Duval Motors discounts genuine MB parts. Check autohausaz.com, they sell OEM and sometimes it's cheaper, sometimes not.