I'm not sure when Piccolino was developed. It's essentially a smaller spinoff of other Crystal products, scaled specifically for headphone cable use. Gabi explained to me that it's meant expressly for this purpose, that its insulation and everything about it is meant for being as flexible and durable as possible. I don't think it was developed for Jaben alone, but it isn't something that Crystal promotes directly. I could be wrong. It isn't limited edition although they don't produce massive amounts of it. To my knowledge, it's made in house at Crystal, which explains why it costs what it does.
Piccolo I believe is significantly larger and stiffer, and is an interconnect wire. It is solidcore, I think. Whereas Piccolino is quite tiny and is very flexible due to being stranded at its core.
Not just everyone can buy it. I basically had to be interviewed, and had to be an actual member of the trade, just to buy a small amount to try out for myself. Typically minimum order quantity is pretty high for it, to the tune of five figures USD, although Gabi may make exceptions. She wants the product to be properly represented essentially, she doesn't want Piccolino to be everywhere in everybody's builds, the finished product is intended to look nice. Just like if you were a big company such as Audioquest...would you take your top cable, break it down into its substituent wires, then let every DIYer on the block buy it direct from you by the foot and make cables of varying success and appearance then post the results all over the internet? Jaben is a skilled and experienced reseller with stores all over the world, so they were the right fit to build cables with this wire. It takes essentially custom tools to work with it and many people who don't know what they're in for are going to mangle the wire trying to make something out of it.
Disclaimer: I have no opinion of Crystal products, I do not resell Crystal products, I have never built anything commercially with Crystal products, etc etc