Quite, lets go for the % increase. Lets stay united and not get distracted.
The problem with your idea is that the junior guys will end up in the expensive places eg NRT and HKG, having to stay in their room because they can't afford the £7 beer. Meanwhile the senior guys will develop a sudden fondness of jet lag free, warm, cheap africa with its golf courses. So the big boys with the cash end up living like kings with juniors living like paupers. If you alter the DOA for different destinations then this will just mirror the present system.
Cheers