DJs have a promotion where if you buy x2 pair or more you save 25% off the listed price.
Random sale pair for $10: here
Gift box for $25: here
Total: $26.25 with free C&C or $10 delivery. Works out to be only $6.56 a pair.
You can reduce the cost even further if you managed to get DJ GC's at 20% off bringing the total cost down to $5.25 per pair.
If you didn't manage to get any you can still get 10% off GCs with the entertainment book bringing the total cost down to $5.90.
Or if if you stocked up on free $10 DJ gift cards with the recent WW promotion they're essentially free.
Not bad for Happy Socks, cheapest I've seen in a while.
For anyone wondering: "Happy Socks was created with one vision in mind; turn a pair of socks - an everyday accessory - into a designed colourful item that also spreads happiness"