The choice of modelling apps is individual.  What works for one person doesn't necessarily work for another.

There are free apps like Blender, Wings, trueSpace and anim8or.

Hexagon can be purchased for the price of the DAZ Characters, Figures and Avatar's book from Amazon.

For purchase range from low (for modellers) up to the mortage the house prices.

There is Silo, Houdini, Modo, Lightwave, ZBrush, Mudbox, 3DCoat, XSI, Max and Maya.

If a for pay has a demo, download it and try it.  Just keep trying ones until you find one that works for you.