Think the rating would be in the range of 13-14.000£. Pretty expensive me thinks, for a light turbo-prop. Maybe stepping up a notch for a 737 rating would be more rewarding, if paying your own rating is an option in the first place.
A tip for the interview; heard they“re madly in love with questions on New PANS-OPS; speeds in different missed app. segments, speed restrictions for cat. B etc.