How long is drive to Aix en Provence? And is there a particularly nice/more scenic way to drive there?
Two hours if you take the motorway, twice as much (or more) if you take the scenic road.
See www.viamichelin.com for a choice of itineraries, add 20 to 30% to the time indicated as Michelin does not take stops into account.
Don't know weather to drive or train, price wise is much same maybe? Fuel.etc?
If I rent a car probably do 3 days or so and explore other areas,it's probably handy for seeing the hilltowns?
Versus train and then get bus to the towns?
Did you look at the michelin site? They give an estimation of fuel and toll costs.
Train tickets : see www.sncf.com
A car will certainly give you more freedom.