That's probably the deal I got in on for my backup ESV. They were 'open box' and mine was very old (middle of the first 100), defective, had the top slider 'all the way up' and the battery stone dead. IMO it was a 'problem unit' VN replaced the easy way and never returned. Joe put it right, of course, but in the process told me if he'd known of the 'sale' he'd have bought them all back since that price was below wholesale (they took a loss on 'old stock').
I just checked, I ordered mine the first week in February, I believe the last one went a few days later. When a friend decided a week later that he wanted one, they were gone.
I would not hold my breath waiting on another half price opportunity. I don't think that'll happen again.
Besides, better to be enjoying one than constantly searching for the deal that may never come?
OF