Quoting Milk Monster:" Thanks ladies! Yes we can afford the extra $30 but.. I'm at a point where I'd rather put that $30 towards ... [snip!] ... I supposed? The main thing is my diploma. I just don't want to regret not walking. I'm flip flopping on the decision so much!"
I'd do the ceremony. Seriously, will $30 make that big a difference at Christmas? In 5 years will you remember waht that 30 bought? Probably not. I doubt you'll be like "shoot, I really wish I could have bought the kids one more toy with that $30!" But you might be like "shoot, I worked hard to graduate high school. I wish I'd "celebrated it" and gotten to do a ceremony.