Besides Racquets and Runners (along Oak St. and 33rd Ave), there's not much choice in the lower mainland. Mind you, they're more for volleyball. I ordered mine online.
Mizuno's shoes are not specific to volleyball from what I recall. They are specific to indoor court shoes, and they've got several that are suitable for badminton. The same go for Asics indoor shoes.
I believe that many of the models are marketed specifically as volleyball shoes (at least the ones I came across in local area and on the web). As general indoor court shoes, some of them are just too heavy to be badminton shoes.
You are right. Mizuno badminton shoes models start with 7K... and voleyball 9K... The badminton shoes are lighter compared with voleyball ones.