In just having to deal with roommates for the last few years, and being the one that is required to collect the money and pay the bills, I'll tell you that collecting money from people is just as bad as pulling teeth. It's amazing that people remember everything about being owed money, but the second they owe money, they forget all about it until you ask them for the 25th time.
and then you're the asshole cuz you want the money to pay for the roof over their head
my roommate is gone, i highly doubt i will ever have another. it's not worth it, i'm the bad guy cuz i want my money