What kind of a car should you rent?
From Friday at 12:00 PM to Monday at 9:00 AM, you can get a Mercedes-Benz S500 or BMW 730d for €136 ($160) for the entire weekend. I once got upgraded to a VW Phaeton V-10 (Sweet! I have a MPEG of me driving one at 265 km/h). If you can't afford that, I think a VW Golf is €85.
If you went thru Europcar, I am not sure if their weekend specials allow dropping cars off at another station. However, Sixt did though but their weekend rates were slightly higher.
If you're not arriving on Friday, then a VW Golf TDI can be had for €80 a day.