PetValu pet store sells the single critter nation cage ……. if you attach 2 of them side by side, you will have a wonderful cage - very easy to do. You could also stack them but it would be a lot of work - creating a hole, ordering a top level pan & ladder. You could contact them to find out the cost.
http://petvalu.com/small-pets/cages...critter-nation-single-unit-with-stand-midwest
Flowertown in Ontario sells double CNs for $375 but they do not have free shipping. You could contact them and ask for a quote re total price including tax and shipping. (They also sell food, and other supplies for ratties - I order from them approx. every 3 months), They also sell FNs, etc and large rabbit cages etc but they have plastic bases
https://www.chinchilla.ca/detail.php?ProductID=MW162
PetSmart was selling a less expensive knockoff of the critter nation cage but stopped at the end of 2018/early 2019. PetSmart has come out with a different cage for rats - another knockoff - but the cage is poorly designed and the floor space is too small - rats need a cage with a base at least 30 in by 18 in because horizontal space is essential.
You can look around and see if anyone has a used CN or FN for sale, but it is likely similar to NB in that good used cages are rare finds.
Amazon.ca sells critter nation cages and has free shipping which I assume includes Newfoundland, but the double critter nation cage does sell for over $500 ….. Ferret Nation cages are a bit less expensive and if you bought one they would be ok if you covered the outside with hardware cloth. I have heard that using hardware cloth is a pain.
You may be able to find another supplier that has free shipping.
You could purchase large rabbit cages (like 60 inches long), add home made levels, cover the outside with hardware cloth, and attach them together. It will be a pain to clean etc but would work (see Reference Thread
https://www.ratshackforum.com/threads/reference-thread-read-only.35894/)
If you know anyone in NB that might be driving to Newfoundland you could order a double CN from the USA or a martins powder coated R695 with flip top lid (martinscages.com, wire floors need to be covered), have it mailed to an address such as a store in Calais Maine and have someone drive it over the border and drive it to you - if you order from martins cages I would strongly suggest you also get the large powder coated playpen - a wise and amazing item. Driving items across the border is important because brokerage fees can be in the 100s of dollars
Good luck