Howto safely go from 230V to 12 Volts
I found this one http://www.ebay.com/itm/New-40W-12V-Halogen-LED-Lamp-Electronic-Transformer-Power-Supply-Driver-Adapter-/251333442321?pt=US_Lighting_Parts_and_Accessories&amp;hash=item3a84a3fb11

Which looks like a solution. The only problem is quality and safety...

EDIT @Anthony pointed out the very important thing that these are AC and not DC transformers so found this one

http://www.ebay.com/itm/40W-12V-LED-DRIVER-CONSTANT-CURRENT-POWER-SUPPLY-TRANSFORMER-FOR-MR16-MR11-LEDS-/161077334059?pt=AU_Lighting_Fans&amp;hash=item2580f5102b