Do you have a pre-set number of packs and items set up ahead of time for a certain period of time?
We develop a set of these packs (we call them a 'Shipment') at one time. Shipment 1 will have 4 packs associated with them (not counting the cheap pack), with one additional pack coming out before Rise of the Hutts. After that, a new shipment will come out, likely with a new name (instead of 'Cartel Packs', they will be 'Contraband Packs', for example).
Developing a shipment has a long lead time. Most of the art for shipment 2 is already complete, and we are currently in planning stages for shipment 3. This is not to say that we can't slide things around, or pull something forward or get something in a hurry if we see a great idea or if something on the market really sells. But the capacity for this kind of movement is very limited.
We also want these packs to have a reasonable life post-removal. As a result, we philosophically resist actually adjusting the internal math of these packs (i.e. what's in them, at what drop rate) after they've been released, so that the value of the packs is a known quantity. This is not to say we never would do so if there was a serious problem -- but we really don't want to. Short form: there likely will be a time in the future where the GTN is the ONLY place to buy a Skip Tracer's Pack.
Are you afraid that greed will corrupt the game?
The cartel market funds the ability for players to play for free, which has allowed a huge number of players who couldn't or wouldn't play the game to do so now. This has resulted in more dev resources, and larger, more vibrant communities. And we've done so while still making market transactions mostly optional. I'm pretty much in the camp that we're on the Light Side on this, so far at least.
Why do these items currently have a price if they are unsellable?
Some game systems require a value for parts of the game to work. As an example, the GTN needs it to know what base price to set things to (and IIRC, doesn't let you put things up for sale that doesn't have a value). These items are currently hardcoded to not be sold to NPC vendors, despite their internal credit value.
Great follow-up and awesome information I think I am going to have to run out and stock up on a few packs and hold onto the for the future now.