Like juubee, I also use AppShopper to monitor apps I am interested in for price drops. If there is something I really want (like PvZ or Guerrilla Bob) I'll pick them up right away, otherwise I usually try to wait for the inevitable sale.
I don't wait and buy apps for the full price
I wait until apps are on sale.
I don't buy apps.
With all the cool apps that have come out and the ones that are just around the corner I need to correct my previous post. Paying full price lately...
shine on you crazy diamond