The fact that you could find fault in this development says more about you than your argument.
The fact you think paying more for something might somehow automatically make it better says your more interested in ideology than reason or result. The 2% number is arbitrary, since its relative to the nation's GDP. They may need more at some point to procure modern arms. It'll drop considerably once you have the hardware.
Keeping to fixed percentages, especially in times of growth, is a lazy way to budget and leads to things like hammers that cost hundreds of dollars....
http://articles.latimes.com/1986-07-30/news/vw-18804_1_nutThe fact is, there never has been a common NATO fund. There was an agreement each nation would spend a percentage of GDP on their own defense. It's somewhat comical for this president to openly accuse nations of ripping off the US when it's not close to being accurate and he's been a famously professional deadbeat for decades.