Im not sure why people think the upkeep on them is high or expensive, nothing could be further from the truth!! Ive owned four and hardly spent a cent on them at all. The AMG i have will cost me abit more, but the 280SE, 380SL and C180 have cost me near nothing considering the work at least two of those did.
The C55 prices did drop, but has jumped up again when there was none for sale for a few weeks.
You can get some real bargain W210 E55s in good condition now though.