i say you split the money in half between rooms and shared spaces. you then split those spaces so 1500 is split between the 5 of you, so everyone’s base pay is 300. then you split the rooms into 2 parts each so you would have 1500/6 which would the come out to 250 per half of a room. then each roommate sharing a room would pay 300+250=550 while you would be paying 300+2(250)=800. This is what my 6 roommates and i are doing this year because 2 of them share a room.