For Soundwave, get the Walmart mobile app and make it favorite...it won't notify you but if you get in the habit of checkng every coupld days you may just land one at retail price. Also keep an eye on Hasbro Pulse. Shipping isn't cheap, but it may still be better than ePay.
https://hasbropulse.com/products/tra...-battle-3-pack
BB is another story, as the others have said the distribution in Canada was unbelievably bad. That said, last I looked ePay prices weren't horrific...IMHO it's worth trying to find.
EDIT--Most importantly, welcome to the hobby!
