Newegg has the Kaby Lake i5 NUC for $100 off now.

BOXNUC7I5BNH for $300 BOXNUC7I7BNH for $384

a year ago I paid $376 for the Skylake version, with one free 8GB Team DDR4 so it was a decent deal.

Couldn't resist so I got this Kaby Lake version too, this time with space for an internal 2.5" SSD, as it might make a nice media player or something.

This NUC has the same CPU that's in the current i5 MacBook Pro (i5-7200U series), so it should be pretty easy to hack.

I'll post an update after building it up.