My advice:  If you want to get your feet wet modeling, start with a cheap program.  Learn the process, learn the terminology, learn different tools.  If you find that you like modeling, and when you become proficient then upgrade to a more powerful program as your skills cause the first program obsolete. 

Personally I love Hexagon 2.2.  But this is just my opinion based on my experiences.  It has its limitations but it is very easy and intuitive once you get an understanding of modeling.  I also have C4d but it is not as easy as Hex. 

This is just my 2cents so I hope I have helped you some.

GM