how many chains can you name that come with two master links? let alone 2 halflinks.
it's a more expensive chain due to the new design, and the tooling and probably more costs that G or someone else mentioned. The first halflink chains also didn't have any other features apart from being different and innovative.
They were also real expensive and didn't come with ANY link. The plates weren't even connected, little rollers everywhere.
The odyssey chain seems very well designed and i don't think that we would need more master links than they supply.
If we do, then just like with any other chain, we turn to the bike shop and get ourselves a new master link. Or if we're that paranoid, we might just order them in advance along with the chain.
edit: or ditch masterlinks lol