This should work and if you allow plenty of time you’ll have a great trip. This is a wonderful area for having a car if you want to visit tiny medieval mountain villages, scattered art museums and to hunt up great local food. However, I’m not sure the car provides anything except better windows for watching the scenery pass-by if you don’t take about 3 days for the trip. A couple of issues…

Renting a car in one country and returning it in another can double the base rental cost, so check that before making your cost comparison.

I’d be inclined to return the car at the Nice airport. There’s easy access from super-highway and you should be able to avoid some of the toll roads and a bit of of the congestion that results from hordes of tourists trying to drive through the very narrow passage between ocean and mountains. This is another situation to compare the costs. Return at an airport is sometimes more expensive than return in town. Conversely, return at the airport or in a suburb may prove to be cheaper than return in city center — particularly in if-it’s-not-mountainside-it’s-urban Monte Carlo. The roads along the Riviera are clogged with tourists from mid-July to early September.

Well, moderator has explained everything in good detail and there isn’t a lot that I can put light on. Though from my prior experience, I would suggest you to look out for http://www.bestspain… as it is a good car rental comapny and you will surely find a cheap and good car for yourself.