Here's what I did when graduating:
Level 3 friend - I went to a couple like this with friends, just stopped by, Dollar Store card that said congratulations and a pack of cards as an inside joke - a group of us used to play cards in band class

the people outside of the card playing group didn't get anything but my lovely presence.
Level 2 friend - I went to these by myself/with friends, and each got a nice card from the Dollar Store with a nice message, a (cheaper) frame with a photo of us/the group, and a pack of cards for most of them, because they were part of that group.
Level 1 friend is BFF - I had 2, and our parents all knew each other well from over the years, so we went to these parties together. I know my parents gave cash to them, and their parents to me, but I don't remember how much. I got a gift for them too, probably a photo frame with a picture of us. And wrote a long message in a card.
ETA: above post made me think, the level 2 friends' frames were from Dollar Tree, and I added some rhinestones to them for a couple bucks, so like less than $10 for 5 or 6 frames. I still have rhinestones left!
