First was a pack of Learning Wrap-Ups. The set I bought contained addition, subtraction, multiplication, division and fractions. I plan to get them out a few times a week through the summer and require 30 minutes of playing with them. Perhaps they will keep the Lambies skills up during our weeks off.
I also found Senior High: A Home-Designed Form-U-La by Barbara Edtl Shelton. I have heard good things about it, and had it in my Amazon cart. The mom who sold it to me also threw in Cathy Duffy's manual. I have some light reading to do this summer.
Another get-to-take-it-out-of-the-Amazon-cart find was "Do Hard Things" by Brett and Alex Harris. Well worth the $3 I spent.

I found a copy of Harvey's Elementary Grammar and Composition. I may or may not end up using it, but it complements my Mott Media McGuffey's series nicely.
Rounding out my purchases was Answers in Genesis's God's Design for Chemistry: Properties of Matter and Properties of Atoms and Molecules. These are another "I might use it, I might not" purchase, but at $5, you have to get it, right?
I really enjoy our annual sale. What's your best find so far this spring?