Zireael wrote:I suggest 'you pay for half their cargo' and the rest is ok.
Reason why you have to cover for the full cost of the cargo is the trader you're hiring is restricted on where they can go...they have to go dock at the main station.
Were it done as a "regular" cargo contract from the position of the trader rather than the player, the trader would have to pay the up-front costs for the cargo and then get the profits for the contract. THAT would be pointlessly bad from the trader's point of view, because they could instead pay the same amount and get more profit.
But...doing this *SHOULD* increase your cargo contract reputation (by the normal amount for a cargo contract) if the delivery is successful, since you're protecting the NPC trader ship AND the NPC trader ship did not run off with the "free cargo" you just gave them.

(Which implies there's a low chance of the NPC trader ship doing that...)
Going further, to set up such a delivery, you'd probably have to FOLLOW the NPC trader ship through THEIR wormhole to guarantee both ships arriving at the same time. That would at least save you a tiny bit on fuel costs. They could do an intentional misjump to avoid you (but very low chance of that stupid action, like 0.5% ...since it's near-suicide for profit)...or they could dock at another station? (1-10%?)
Maybe the traders you contract with have their cargo reputation mentioned (vaguely?), so you know in advance whether they're likely to desert you.
Cobra 1, 10 tons capacity...Trader of unknown reputation.
Cobra 3, 35 tons capacity...Trader of poor reputation.
Python, 100 tons capacity...Trader of good reputation.
Anaconda, 750 tons capacity...Trader of excellent reputation. (What else would he be doing with an Anaconda?)
Problem is, you can only "fill them up" with cargo from whatever you see on your cargo list...so an Anaconda would likely only get maybe 200 tons of "stuff" or you'd be selling things at a loss.
Might have to limit it to 100 tons max?