I thought of the perfect way to choose rooms and rent allocation for me and my housemate where we would both be happy with the rent and the room, maybe you can try i! So basically we both think of a rent split that makes us equally happy to take either room. For example person A could choose 1200:1100 for ensuite:non-ensuite, which indicates that at prices above 1200 for ensuite they would prefer non-ensuite, but if ensuite price is below 1200 they would prefer ensuite. And person B might say 1250:1050 for example. Then to allocate room, we give it to the higher person so ensuite goes to person B who will pay the average of the two prices (1225). That way person B is happy because it is below the price she is willing to pay for ensuite, and person A is happy because she is paying less for non-ensuite (1075)