Hyundai Coupe 2.0 se (need a key and new fob)

[trace1967]

Hi I have a 2005 plate coupe and only have one key and one fob. The fob case is cracked but battery keeps coming away. I have been trying to find a replacement fob and have been quoted £180 for two fobs and one key.
Tried looking on ebay, the key has a transponder in it and so I dont see why I should have to go to a dealer.

Does anyone know the best way to replace the fob and where i can get them fairly cheap or reconditioned.