Stalling Attitude - not at all! If an airline advertises that it wants B737 rated people with X hours, why on earth should they have to sift though thousands of applications from wannabes that don't have the courtesy to follow the requirements? If the £50 helps separate the men from the boys (as it were) then I also think that it's a good idea.
In the apst, I've been on the receiving end of literally thousands of CVs - of which probably no more than 10% actually met the requirements. However, my team and I had to waste many hours going through each of them.
£50 a shot would have helped out with that pain!