Slotted rotors work, I reckon the pad bite is unreal.
However no, I don't appreciate the price difference.
I buy standard rotors for 70-90 bucks a pair and send them to a CNC machinist friend who slots all my new rotors for a quick cash job. I generally end up at least 50 bucks and sometimes well over 100 bucks ahead of buying them from RDA/DBA etc
All that needs to happen is to set out an inner radius of pad area, an outer, and to make some arcs any slight radius rouhgly 6 times over the rotor. Then flip over... An easy task for any CNC machinist who knows what they're doing with a bullnose bit.
Alternatively, I reckon the Sumitomo calipers are more than enough for a Skyline... Just a decent set of pads and standard rotors should do.