Alright, in further research, it appears that we cannot take the train over the Pyrenees, so that leaves that out. I have found a car rental agency in Hendaye and one in San Sebastian. This is causing me to rethink my idea of only doing the Catalan Pyrenees. After looking at viamichelin, it looks just as do-able to drive through Toulouse and the Pyrenees to Hendaye to drop off the car, then pick one up in San Sebastian and drive back on the other side of the Pyrenees to Barcelona. If I was not selecting an automatic, it would be about $340 for ten days. If I select an automatic, it is $450 for ten days picking up in Monte Carlo. I am fine driving manual transmissions anywhere except mountains, so am selecting automatic so I know that also is raising the price. The cost of a one-way from Donostia-San Sebastian to Barcelona for three days is only about $165. So, all in for 13 days, about $615 vs $1450 if I rented a car from Monte Carlo to Barcelona. This definitely makes it more palatable. I'd still like to get that price lower, but for two weeks and the ability to tour all of Provence, the French Pyrenees, and then the Spanish side of the Pyrenees on the way back, I can't really complain.

Thanks for the input.