I'm currently driving through France heading for Portugal and I've gone for the 'toll road' option which will cost me about 100 Euros in tolls (slightly less actually) and will take a projected 16 hours:
I did have the option of avoided the 100 Euros in tolls and going via entirely free roads, but that would have taken me around 20 hours.
As far as I can tell paying for the toll roads is a no-brainer... that longer non toll route adding on 4 hours of driving is around 250 miles, which is equivalent to about 25-30 Euros of fuel add on another couple of expensive coffees and meals to see me through that additional driving = say 40 Euros,
Then add on 4 hours at minimum wage for working, 10 EU/ hour, which I can do if I go the faster route, and I'm left with a total net cost of taking the toll roads of 20 Euros, and I get a better quality of Aire as well! lIke the one I'm sitting in right now, practically on my own!
There's also the fact that an extra four hours of driving means more chance of getting caught in traffic - I've already been delayed by 4 hours because of accidents, so that extra time could end up adding another entire day on to my trip, meaning the 'free' roads would end up being more expensive than the toll roads!
What's not worth it is feeling like a twatt every time I have to get out of the car at a toll booth because I can't reach the card machine!
Oh well, not too many of them left now!