In my game, I wouldn't let anyone get ahold of stuff that's Expensive++ at chargen. Beyond that, they'd need some serious rep and good networking skills to get a hold of the blueprints (and I'd be slapping some penalties on those networking tests). Some items, like spacecraft, are expensive enough that we don't even provide costs.

Dreamy open source future aside, as a GM, one has to consider game balance. Fortunately, there are some good justifications for limiting access to items in the 'Expensive' category. Insystem, state of the art designs for complex items are controlled by fierce intellectual property laws. Start fabbing hyperbaric micromissiles off a Valles-New Shanghai souk, and you'll have a tac squad with a copyright violation warrant breaking down your door.

Outsystem, you might be able to get the blueprint, but actually fabbing the item could be a problem. You'll note that in the items descriptions, some Expensive items contain mats like antimatter, qubits, or heavy metals that are rare or hard to come by outsystem. (Antimatter and other rare mats are treasure; make your PCs work for them).