Interesting Question - I live in Canada and have purchased my last 2 RV's (The latest being a Montana 2955RL) from the States. I found the prices better and the dealers much easier to deal with. Canadian dealers do not seem to want to give you any kind of figure - you have to make an offer, argue about it then wait for the inevitable "Well I had better go talk to my manager"!!!
My dealings with the US dealers have always been very straight forward and I been able to negotiate a basic price over the phone (As I knew exactly what I wanted) then travelled down and finalized the sale (Adding extra goodies and getting the price moved a bit at that time.)
If any Canadian is contemplating purchasing from the US it is very easy. In fact the first time I brought my new trailer across the border into Canada the customs guys never even came out to look at it!. They only wanted the GST. There is NO Duty except $100 for the air conditioning unit (don't ask me why) There is a fee of approximately $150 to the Registrar of Imported Vehicles) and a minor test to be done by Canadian Tire. More info is available at
www.riv.ca
There is no warranty problem as there are Montana dealerships in Canada.
Good Luck.