The price is more expensive then doing there TR normally, factor in accommodation, food and travel. Granted Taxis are cheap there.
All that is happening is a Chance, thats it, a chance, not for an interview but to the first round, there are 3 rounds, this would let you skip your CV because you dont have the hours.
Im assuming its the same as the NTR and TR first officer route so you go to Southampton to do
day 1:-Interview, group exercises, presentation
day 2:- Simulator
day 3:- Dubai, interview, medical.
Now note from experience there will be about 8 of you there, this number almost always gets down to two that make it to day 3.
With it being at Southampton you will probably be there with other TR guys. with hours on type.
Thats a lot of money to pay, for a chance to get your CV skipped, then onto your 25% chance of making it to day 3.