Shipping is the killer for me. Shipping to Canada from the US is minimum $30-40 for a kit. This puts a serious pinch on buying kits. The initial buy-in has to be stupid cheap in order to make a purchase worth while. For me, this makes any currently available kit purchase untenable. In the last five years I have bought maybe five or six kits on ebay, all vintage, all much wanted and searched-for kits, all snagged for unusually low prices.
Curiously, all other countries are much cheaper to ship from, with the possible exception of Australia. It is almost always cheaper to order from, say, UK, Poland, Germany, Ukraine, or Japan, etc. than from the dozens on offer on this continent.