La Senza Canada: BOGO Bras!
Right now at La Senza online, you can buy 1 bra and get a 2nd for free!
When you add 2 bras to your shopping cart, the lower priced one will reduce to zero.
It's a limited time offer, but it doesn't say when it will end. There are lots of bras to choose from, and prices start at $32.50 and upwards. Some of their choices are quite nice, such as this Itec or the Lace Push Up Bra.
I'm usually the same bra size no matter what store I visit, so I have no problem with buying underwear online. I've bought bras from La Senza Canada quite a few times.
I don't know if this offer is in-store as well - if anyone happens to see, please leave a comment below.