Look no further than the Nordstrom half yearly sale. Note that I am focusing on the female grads in your life- Nordstrom is great for dudes but that's not my specialty.
This Hobo pleated patent leather clutch is only $51.90 (originally $78) and comes in several other colors, including black and sun. I just picked this up for my sis, who is having a bad week and needs a little happy. But this would make a great, affordable graduation gift.
Some other suggestions:
Leather business card holder in a fun color- or an embellished one if that is more her speed. This leather Lodis business card holder is only $32 and comes in 6 colors (and can typically be found at Nordstrom):
Cocktail ring- buying costume jewelry isn't weird if they already like accessories. This candy colored Kate Spade ring is $26.90 (originally $55):
A large scarf or wrap is also a good choice. If your grad is going to Europe for the summer or moving somewhere warm, consider a linen scarf (these are $32.90):
And if she is going somewhere colder? These fabulous cashmere wraps are only $98 and come in a ridiculous number of colors:
And if all else fails: get a gift card- then she can select whatever she wants!