Most places seem to charge 5-15 dollars apiece for a cutting, depending on the type. Like I said, I got most of mine on ebay. This place has a good selection, although I can't say I've bought anything from him.
I made mine 6 ft so i could get under it easily with the mower... however lower would produce quicker.
I bought from that dude too, because of price, shit better be as described...I planted them last weekend into a pot that I made after seeing your idea...I went way gullier with it though. I'll post pics tomorrow.