The San Diego Comic Con exclusives get earlier every year.
In August, IDW are publishing Dave Stevens: Complete Sketches & Studies, collecting all four of his sketchbooks, long out of print, in a hardcover volume.
But they're making the collection available a few weeks earlier at San Diego Comic Con. You can order copies now, one cover (left) available for Comic Con, mail order and for shipping to retailers, and one cover (right) exclusive to purchase or pick up at Con and limited to 300 copies. Each is prices at $50.