I would even check with Canada Post for delivering heavy items. I was surprised when I ordered a relatively heavy table saw and band saw for
wood and it was delivered Canada Post. I had to get it at the loading
dock of the post office, but the post master said they can handle most items and regularly receive big items.
Just have to see if their rates are any better for large parcel. Also not sure if USPS is able to do the same on the other side of the border though.
There used to be 3rd party
shipping companies on the US side that had reasonable rates & brokerage compared to the top ones like UPS & FedEx. Can't think of them off the top of my
head right now, I used to receive lots of industrial
equipment that way at a previous job. Just may require some
shopping around.