Canvape are the largest and have the best prices, but they are total DB's if you have an issue. They only take Interact so you have no recourse like you would with Paypal or a CC if you have a problem. Facebook is full of hate for Canvape and I refuse to buy from them and GearBest (also DB's.)
I order from China (FT, 3F, FC) or from US vendors that have a good shipping price like Lightning Vapes or Sweet Vapes. Even with the conversion and shipping, US sites beat local B&M prices by quite a bit and usually Canadian online prices as well. Like corn flakes said it all really depends on what you are looking for.
I recently picked up 4 25R5's and 4 HG2's from LV for $10 each after conversion, shipping was $9 and took a week and a half. The local B&M wants $18 for LG's and $20 for HG2's. If I drive an hour I can pick up the LG's for $15 each and the HG2's for $17 each. Don't forget those prices still require the 15% sales tax (NS) and gas if I drive the hour to save $3 each.
I don't mind paying a bit extra for a local purchase, I realize the shop owner is trying to make a living but I will not be gouged from them.