What model iPhone Buy Movistar Spain?

. Mike Puchol (the creator of two very interesting tools for WiFi, as StumbVerter and Whish) has made a surprisingly simple, which model and data plan and voice have to choose if we want to buy an iPhone3G in Spain based on price sale of each model iPhone3G, fertilizers services to be hired for each price level, and the total acquisition cost of each variable:


In short, the calculations confirm that we should buy the 16GB version, because in any event is between 2% and 7% more expensive than the 8 Gb version

And you? Do you do calculations? What models prefer? What data plan?