Thanks to readers @all_makeupt and @moonpowermakeup on Instagram for the tips about this one!
Right now on the Kohl's website (I do NOT know when this sale ends or if it's going on in-store), all Real Techniques single brushes are Buy 1 Get 1 for $1 HERE. This does NOT exclude the Bold Metals collection, but it does exclude sets. Just add two qualifying brushes to your cart and the lowest priced brush will be $1. There doesn't seem to be a limit on this offer, but you obviously need to add an even number of brushes to your cart to get the maximum savings.
There are various codes you can try to use with this deal HERE (remember, Real Techniques is not considered prestige, therefore coupons apply!). Also remember that you can select "PICK UP IN STORE" in the item listing to avoid all shipping fees. Otherwise, your order will ship free when you hit $50 (through 11/27).
Thanks again, @all_makeupt and @moonpowermakeup, for the hot tip!