I was a fan of NoNumber Extensions
Peter van Westen is doing a good job and he produces a lot of extensions which makes the maintenance of a website easy.
On my pages about his extensions I did make some explanations in German. I gave it up because of Peters price escalation on the 6. April 2012. He screwed up the price astronomical.
So I believe even considering that he has to live and earn money te price he is now asking is too much. So I gave up to support a fair developer which turned out as a cash-hungry moneymaker. Sorry for that.