Prices will obviously increase in 2.0, as there were too many "never-heard-of-em" players owning vehicles.
Especially high end sports cars, since there should be a difference in the economic status of a cab driver and a multi-millionaire. So limos/comets will be much costlier than the regina/manana stuff.
But dont worry, money making opportunities will increase too. (apart from cops)
About the /c sellcar command:
If /c sellcar pays full cash back....then we cant have SSA and Roxor business.
Choose between the businesses or /c sellcar.
I personally hate it when people change cars like they are clothes.
If you made a decision, and bought a car.....then stick to it.
It kinda enhances your decision making skills....and will help ya' life, if you got any...