I'm sure these guys have done there sums, if you lease a stand then you must have your own costing structure - Signature have stands 16/17 for years, they are not per hour on airport rates. Signature & Harrods regularly burst at the seams with traffic, we all know biz traffic goes to other airports because they cannot cope - hope this is not another bash from Essex!
As far as the M1, you obviously haven’t travelled down 4/5 line bliss recently!