It does (or it should) make sense. For every 10 seats, you have 18 standing (it is claimed people take up more room standing so you can't just double the number from 10 seats to 20 standing).
So an area of 3,000 seats becomes 5,400 standing.
3,000 x £45 = £135,000
5,400 x £35 = £189,000 - even at £30 it is £162,000
i see what your saying but you forgot the price of more stewarding and police for extra fans that's the cost we don't see. but safe standing has got to happen or fans who stand up could be only one game away causing disaster and we don't want to see that. so for me the taylor report into football stadiums being all seats need to be review and is so out of date and modern stadiums are not safe for fan to stand up in seated areas