wow, i just checked prices for op-1 and you can get them new for 655 € !?!
check this page for an overview
http://www.idealo.de/preisvergleich/OffersOfProduct/4195305_-op-1-teenage-engineering.html
even when i’m not sure if i need/want an op-1, i think the price is pretty good! so if you are thinking about getting one, you should grab it now. (and i think about getting one or save up for a RYTM).