Firget price. The No 1 advantage of flying in the US is time efficiency, due to weather. You will lose so many training days in the UK due to weather. When the plane is yours the weather won't be good enough, and when it is everyone else wants to use the aircraft. The US is perfect for training quickly and hour building efficiently. When you are training you are learning a motor skill and the more frequently you train the more you will retain and the cheaper it will become.