I have a scenario where I have 2 groups of people registering for the same event. Each event has a max capacity (lets say 15). The first group (premium) can register at any time and pay either a discounted or no fee. The second group (standard) can only register within X hours or days before the event, and pay a different rate than the premium members, and only of there are still spots available for the event. Is this configuration possible without custom code?