You can order a custom iPhone case for $9.99 from VistaPrint.
Shipping and processing starts at $4.34 per order and there is also a $1.49 PDF proof fee. So, the total will be $15.82 — not bad for a personalized gift like this.
Too bad I have a cheap Android. Well, I might have just saved myself some money, in addition to the cost of the phone. :)