Is it possible to have user groups that expire?
For examble, all our costumers can be basic. This gives us info and stats, and is of course "free". The pricing is depending of time of day and week.
Then we have Gamer profile. Able to play all of our games, and surf with traffic limit. They deposit money on their account, and the rate is depending on the hour of day and week, and is cheaper than basic. This costs x pr week/month/year
The we have VIP costumers. They can play all of our games. Have higher traffic limit (btw we pay pr MB in Greenland for internet) and the price is lower at all times. This will be more expensive pr week/moth/year.
If for some reason a VIP does not have the funds at the end of the month (or whatever timeline) to cover his fee for staying in VIP, he will get "bumped" to gamer or basic profile at his choice at next login, or opt to accept VIP charge to his/her credit card and stay VIP.
The same with gamer profile, except they don´t store credit cards on the profile, and have to pay at the desk and get credited status by operator.
This is just an idea of what I´d like to have. Let me know if there are any flaws or possibilities.