+1. He's the only one from whom I was able to get these in bulk at a less than $0.50/blade price. I obtained them through Ebay. As an aside, after dealing with $3.00 cartridges for so long which lasted only about 6 shaves for me, I'm astonished that I am trying to drive the $0.50 price point (translating to a week of shaves for $0.75) down even lower.
depending on where you get them from the ones in the black box are +1 free. so you can get 6 blades for the price of 5. so that lowers your .75 cents/week cost even further.
I don't get the black ones...never tried them myself, but some people LOVE them (in fact, the guy that runs Shoebox will often get 14-20 shaves per blade...and this was BEFORE he opened shop, so it's not like he's talking them up in order to sell them). Others think they are merely ok...somewhere between the greens and the yellows. From what I gather, the blacks suffer somewhat from inconsistant quality. They are an extreme example of YMMV, lol.