Yeah no idea why people are overcharging for these S7s. A buddy of mine picked up a bunch for $350 CAD each 2 months ago.
I don't know, maybe it is something to do with the fact that btc price was USD 595 two months ago, a.k.a almost 20% lower.
Since btc price was increasing steadily lately, people tend to project it forward (rightly or wrongly).
If btc moves to $1000 fast enough, those S7 would go for $500-600.