Does anyone know the cheapest price for an Xbox One controller? I'm totally fine with Wired controllers... the cheapest one I seem to be able to find is the lime green Rock Candy one on Amazon for $36.
If you don't mind a used one, you could try the Amazon Warehouse (their used section). There's a dedicated thread in the video game deals section you could sub to and a lot of other CAGs post links to great deals.
Other then that, I don't know of any current sales or promotions, but you could browse the trading section of the forums. Maybe another CAG has a controller for sale or trade.
Sorry I wasn't of more assistance but I hope that this helps out some.
Check that thread for details but basically it boils down to if you buy an X1 controller you get 500 My BestBuy reward points, which equals to a $10 off certificate.