There is no doubt you can obtain deals far better in the USA, than in Canada. However be aware of the following:
US Vehicles must be electronically reported to USCBP prior to export. This must be done electronically and by a US resident or US registered corporation, failure to do so will result in our CBSA refusing entry to Canada unless proof of export is provided and a nasty fine.
Look at Registrar of Imported Vehicles
and verify the unit is allowed import to Canada, if it is >15 years, then you are exempt. They also provide an easy checklist to follow. This applies to the chasis portion ONLY, not the "house" portion. CBSA will complete the entry process for you and GST/PST (HST), plus $100 excise tax for air conditioning will be payable. You can complete the RIV process on-line and once inspected at your local Crappy Tire, you will be good to plate it. Also be sure to get interim binder of insurance for transport home.
Lastly and contrary to "it was on Google so it must be fact", RV's in Canada must have their propane, plumbing and electrical systems approved by CSA and each Province has different regulations regarding above in addition to CSA. The Federal Gov't has nothing to do with this. Now, lots of people say once the propane system is approved by a Provincial inspection, ignore the rest...careful and make sure you verify with your insurance provider (not provincial motor vehicles) that they are aware the unit will not be CSA approved and that coverage will be provided in he event of a plumbing or electrical malfunction. Again lots of people believe this is not an issue, but it is.
Good luck in your search!