You can still PM sellers in the cargo hold.
For me I've started with trying to acquire the cheapest and completed accessories that need little to no work: flak vest, gloves, braids, neck seal, belts, etc..
Now I'm looking to get the hard parts, either completed or needing work.
I'm currently working on a poor jetpack kit from outside TDH (shame on me for not join sooner), which I thought would be the hardest to acquire and work on.
Getting as many of the easy parts keeps me motivated, knowing that I am almost there, and need to finish. When in actuality I still have a long way to go:rolleyes