I read about his garage sales on his blog! Have you gone before?
I have, yes, as he lives right around the corner from me. I was even his hired hand at the one he just had last weekend.
He had a "driveway" con, which unfortunately I could not attend. In attendance: him, Mike Barr, and Tom Batuik (Funky Winkerbean). Would have been fun...
As far as the merchandise? Great stuff! .25 comic books (you may find some Walking Dead in there), $2.00 brand new GN's, and $5.00 (sometimes unopened) HC's! It's fun, he tells a lot of cool stories from back in the day, and I can think of worse ways to spend a Saturday morning!