You can buy a replacement Key fob for around 15 euros from eBay (not genuine). I managed to find a genuine Alfa one, and swapped the circuit board and key blade over. Result was a brand new looking key for 25 euros.
My key fob has a screw in it to release the battery that has completely worn down so I may have to break to fob to get the circuitry and key blade. Mine looks exactly like this out, will this case take my key blade and circuit board....is it an easy switch to make?