well, One way I can think of is potentially the seller had some way to rack up tons of Peaks Rewards points and wanted to "cash" them in.
Just like how I know at some safeways the checker don't use the store's courtesy card but their own personal card for all the folks who don't have one but still want to get the discounts, and now pay $.10/gallon for gas
Perhaps selling off 15 tickets is easier than selling them off in drips and drabs, but surprised he wouldn't want to get easily 25% more for his vouchers.
If I were you, and was not worried about the deal being legit, I'd lock it down rather then hoping something better comes along.
You're not going to do better.
btw (not the forum police) but this forum area really isn't a buy/sell craigslist board, so your post was a bit self-serving, but it looks like the thread ran it's course.
There's a buy/sell area if that's what you want to do for the future.