I'm glad someone is talking about this. We are picking up in Zurich & dropping in Avignon, 13 day rental for $531.00 for car & then $561.00 for drop off!...but trains schedules & prices & inconvenience means we will just pay it. I have to say in Mexico they charge about $800.00US for 7 days so comparatively it's a deal!

Our 21-day (we always rent in full 7 day increments for the best per diem price) rental for a compact wagon, in and out of Geneva airport, totalled $710.95[US].

We avoid any drop off fee by returning to the point of pick-up and I design our itinerary as a loop so there's no re-tracing.

I just checked again and now see a $50 drop fee on orbitz across the board on my trip (this is Brussels/Paris):
Daily rate 47.34
One-way drop-off fee 55.00
Total car rental estimate 127.46 EUR
Amount due now
Amount due at pick-up
Car rental estimate including taxes and fees plus 55.00 drop-off fee . 127.46 EUR
Daily rate does not include taxes and fees or 55.00 one-way drop-off fee. Rental fees are due when you pick-up your vehicle.

yeah, next trip I will consider the same pickup/dropoff point...but we have FF miles Free First Class LAX to Zurich & then Paris to LAX....I guess the car fees are really a show stopper. But it will be my first point of consideration on future trips. Last year we picked up in Rome & dropped in Venice so no big fee there.