The worst job at any club must be reserve goalkeeper.
I'd be extremely surprised if Cech left us. He seems very happy at Chelsea and I think his contract was recently extended into the far future. I'm not sure Courtois will ever play for us. He has done fabulously well at Atletico and seems to be happy there. Why would he leave Spain to be number two to Cech?
Maybe Butland should be number two to Cech for a while or be loaned out to some Premiership club. If we do buy him for £3.5m we'll very likely make a big profit out of him in a few years if he doesn't end up replacing Cech. It's a silly price.
I think both Turnbull and Hilario have been adequate reserve keepers. Hilario's getting on a bit. Perhaps he has a juicy bit of gossip about Roman he is keeping to himself.