Looking today in the book I picked up from them when I got my license it varies really by age when you buy it. I seem to recall the prices now are $300, $400 or $500 depending on how old you are.
I've forgotten what it was when I first became aware of it but adding up the then cost of license and multiplying by the years I had left until 65 it was less money to pay annually and didn't have to put all it out up front.