Interstellar Mail Order in Traveller

I haven't seen Traveller rules for interstellar mail order.  What if you don't have time to visit a high-tech or low-law-level world where the gizmo of your dreams can be found?  Can you get a merchant there to ship it to you?

The trivial case is same-world mail order.  On any world high-tech enough to have a datanet (TL8+) or at least a telephone system (TL6+) and with enough population to have a reasonable number of merchants (Population code 4+, or at least 10000 people), there should be mail order businesses, selling any products that are legal on that world.  Cost should be roughly the same as that of visiting a store, possibly with some additional shipping costs, especially for larger items.

But it gets more complicated across interstellar distances.  The customer needs a copy of the store's recent catalog.  This should be relatively easy to find, at least for larger merchants who broadcast xmail out their catalogs to all nearby systems regularly.  The customer then needs to send an xmail to place the order, along with sufficient funds.  If the customer's current location and the merchant's world have a bank in common (which should be the case for any high-TL high-population worlds within a subsector or so), then the customer can deposit their Imperial credits at the local bank and send an interstellar money order along with their order, typically for a 1% fee.  (If the buyer actually has an account at that bank, they might reduce or even waive the fee.)  The xmail costs the typical Cr 10 / parsec, and typically moves at around Jump 2, faster along xboat routes and major trade routes, slower between backwater planets.

Once the merchant receives the order and the payment, they can ship the goods, assuming they're still available and the price hasn't increased.  Shipping for large items runs at the rates given in GURPS Traveller Interstellar Wars: Cr 700 per dton per parsec on minor trade routes or better, or Cr 800 per dton per parsec on branch routes.  Shipping for smaller items runs into minimum fees: Cr 100 per parsec.  Freight typically moves at about Jump 1, as most cargo ships are Jump 2 but spend about half their time in-system rather than in jump.

That assumes the recipient will be staying put on a known planet.  If they expect their cargo to chase them down, there will be extra time and expense.  First, they'll have to send periodic xmails to update their own location, so their goods can be forwarded.  Second, they'll have to pay for any extra hops their cargo takes, at the usual price.  Third, if they want to be updated on the current location of their items, they need to pay for more xmails, from the item's location to all the worlds they might be.  It all adds up, so it's probably simpler to ship to a world the buyer visits regularly, and pay for storing the item there.  Storage fees for large items can add up: the standard rate at starports is Cr 2 per dton per day, with a Cr 1 per day minimum for small items.