We're hoping to rent a car out of London Sep 14 dropping off on the 22nd in time for our flight from Heathrow. We'll be driving around Wales and Scotland.

The prices we've found seem pretty high. Can anyone offer some ideas on how to keep the costs down to a dull roar?

Even a one way might work if there's a need for relocating vehicles, i.e. take a train to Edinburgh and pick up a car to be returned in London, etc.

I'm wondering if someplace outside London with easy access to Heathrow would be a better bet to rent a car? We're two adults with luggage.

Certainly open to ideas, and would be very grateful for any suggestions.