Skimp on Shipping Insurance
Lots of importers/exporters have to worry about insurance cost because of theft, fire, mechanical failure, atmospheric conditions. Depending on what you ship to whom. For your monks these cost are non existent. The trick is deceiving people in that you are shipping the stuff. You just happen to have that specif item always on hand in there closest warehouse.
Lets give some examples
* Anti-venom/toxins: Lots of expense easily spoil-able medicine (and rare blood types) out there that hospital just don't stock-up and order only when a person enter's bitten by that specific creature. Have a small warehouse in each major city and advertise you have a stock of every type of anti-venom in every one of them. You only have one central warehouse staffed by monks.
* Fresh Seafood Build small aquariums in big cities and again advertise you have a large supply of Seafood shipped overnight still fresh still alive in some cases. Restaurants and other catering services will pay you more money for that service than they will charge their customers, The prestige of having still living wild tuna freshly caught from the other side of the globe is worth allot. also as a bonus lots of restaurants would see there food waste decrease if they don't have to pre-order a day in advance.
* LEO Already suggested by others but send a empty rocket into space then if the launch is successful. Which is not a guarantee, (which is why insurance is expensive on launches). They teleport the food, water and/or spare parts up there. 500
Unfortunately you wont be able to transport specialty parts because you wont be able to explain them surviving a crash. Just offer it as a cheap service using old rockets engine with high change of failure. These regular supply runs can be very profitable if you only send up air and fill it up once in orbit. While commercial space flight is in its infancy. A estimate for cost charged per kilo to the ISS can vary between 20.000 and 100.000 dollars.
* Diplomatic mail. Lots and lots of things gets shipped through diplomatic pouches every day. They are handled by commercial shipping companies like any other but they over a tantalizing benefit nobody is allowed to open them. Again you can overbook private charter flights. Advertise you offer secrecy above all. Nobody will know what route it took to reach its destination. If a plane is lots by accident just claim its contents where private. The first res ponders already removed the cargo before other people showed up or just say it was flying empty which was the truth. 500