We paid out of pocket. I don't think we had a max that we could spend, but people usually didn't go too crazy.
During the first part of the NM period, each NM is paired up with first an Alpha sister (usually whoever preffed her), then an Epsilon sister (usually someone the NM doesn't know that well, to mix things up). Alpha and Epsilon sisters usually get little gifts for the NMs, make sure their dorm room doors are decorated, maybe take them out for lunch or dinner, etc. Then the NMs are matched up with Phi sisters, who are their bigs. Then the spoiling begins
ETA: Of course, the NMs get bid day gifts too. These come from the new member educator's budget. We're proud of our NMs, and waste no time slapping a ribbon and a t-shirt on each of them