Eh Canada Paul , where abouts are you? I'm in Chilliwack only 20 mins from th border so shopping across the border is easy for me. any how Harbor Freight is just 45 minutes from here and the their trailers come unassembled in a box so I think its just considered parts (as that is all it is at that stage) duty on those would only be minimum. You may be able to have one shipped to a border town that has a "Ship happens" or "Package Express" and they only charge minimum as well maybe $10 or so.
Buying a welder is what I ended up doing with the intentions of selling afterwords but as it turns out I love the fact I can weld anything I want at any time as needed. So the Lincoln 180 stays. Welding your own trailer is not that hard when you have welder friends who will help for a cold beer
PS Try Princess Auto, if not for trailer for te axles and springs or torsion axles, lights, there's one in Lethbridge