This is a picture of a yarn diet. :-)
I am kicking myself ... I bought just enough yarn to make the Coquette top from Fitted Knits. Of course, while winding the ball it developed mysteriously into a huge crazy tangle. Gah. I stopped at the LYS on my way home from work and they are totally out of not just the dye lot, but the whole damn color. Lots of ones that are similar, none that are the same.
I am going to soldier on with what I've got, and see how far I get. (I was going to shorten it anyway.) If it isn't enough, I will rip back to the bottom ribbing start and redo it in a complementary color, then frog the top ribbing and redo it in the complementary color as well.
Lesson learned: if you don't use the yarn, you can exchange it ... but if you run short, you'll have to come up with a plan B.
On the bright side, my decision to add shaping was definitely the right choice.