Hi!
I'm planning to run 64 20 mA LEDs from one of those MOSFETS.
That price of 142$ includes components for the big 8x8x8 cube, but also for the small 4x4x4 learning cube and some spares. I guess that if I tried to but onyl as many components as necessary for the 8x8x8 cube only, I could have pulled it off for about 100$.
6m of craft wire is definitely not enough. But I have bought 3x6=18m, which is probably twice as much as I need. I do not know how soft or hard it is, I bought it blindly from eBay based on the suggestion of somebody who has already used the same or similar craft wire to build a LED cube successfully. It is 0.8mm thick and is sold rolled up, I'll have to straighten it before soldering.