My cold start valve has been disconnected throughout winter and its always started fine (maybe a couple of seconds slower to fire up than it should, but thats all). What I mean is, don't assume the CSV is vital for starting the engine.
If it was me, I would look at the electrical side of things first: clean all contacts, new plugs, rotor arm, and maybe the coil (??). Then injectors.
As Rowlers said, I bought the merc one's off ebay and they were fab, plus not much more than having the old one's cleaned.
Good luck.
