Not surprised this stuff is sold out with the guaranteed sketch per box, especially considering how the previous Marvel set with the same structure sold. Only reason I didn't go into this is that I'm more of a Marvel fan, but I'll likely still pick up some sketches on the secondary market.
Great luck for you in getting the character sketch you were looking for, and I'd have to agree, you're basically paying for the sketch as even the lower ones will get you about half of that back, so if you hit a rare artist or hot character you'll be golden.
