When I graduated from high school I received all of the items I would need for college. My mom purchased them throughout the year when she found them on sale. I received, bedding, towels, storage containers, small set of cooking supplies, picture frames with pictures of my family and friends already in them, rolls of quarters, stationary, postage stamps, disposable cameras, gifts certificates to local grocery store, flip flops for shower, health and beauty supplies, desk lamp, pretty accessories for my dorm room. It was really a great gift. The best gift though was a very heartfelt card and letter from my dad. He's a man of few words, so this is a cherished keepsake. If there is one more expensive item he really wants - laptop, digital camera, etc. maybe you could offer to pay a portion towards that item. So if he gets a enough graduation money and/or money from a summer job he can get the more expensive thing.
Michelle