After years of using my trusty flip phone, I am considering making the switch to a smart phone.

My question is which plan? 

Verizon has a 2G plan that is pretty much at the upper end of what I want to pay.

'Wireless Cell Phone Plans, Unlimited Talk & Text, Prepaid, & More

They also have a prepaid plan at around $40 for $3G of data.

I don't get it.   why is the postpaid plan more expensive and less data than the prepaid plan?   What am I missing?

I do realize I need to buy my own phone with prepaid.   But don't I also need to do that with the postpaid plan?