I ordered this off amazon because that saved me postage compared to the other sellers which made this a more reasonable price. They didn't have stock at the time, I received email updates and within 7-14 days I received the cartridges.
The livescribe pen is great, but it does need ink. At just over a pound a refill I think this isn't bad (i'm ignoring red as I very much doubt i'll use that). This an original livescribe product - comes in a ridiculously large box for the contents, inside a small envelope with 5 refills. This is livescribe trying to make you perceive this is good value I'm sure and made for retail.
I've bought ink from 3rd parties in the past and haven't been that impressed - ink runs out very fast and the cartridge often ends up with a rough/scratchy application, I'm glad to report that these appear to be fine, so far.
So to summarise.
Packaging is huge and could have been made smaller, my review is for the cartridge and the ink, so I dont really feel I can knock it too much for that!
Yes they are essential, if you want cheap alternatives buy compatible ones, but for me given there is little difference in price I'd prefer to have authentic cartridges.