I went to the first one of these sales a few years ago, somehow I was like 20 back in line at 10:30 when I got off work. I still got some great deals and had the BEST time ever as far as getting some good deals on some nice pistols and a rifle. Yeah, it was not easy getting checked out with background checks and waiting to pay, but it was still worth it.
How about doing a month long sale? don't put everything out at once, but surprise the dedicated shoppers to some mind blowing sale items a few at a time, sell some and then put some more out a little by little?