Plantronics BackBeat Fit
The BackBeat Fit is Plantronics sports Bluetooth headphone and competes with the Beats Powerbeats 2 Wireless, which retails for $200. But the Backbeat Fit has come down in price and can sometimes be had for a little over $100, £70 or AU$160 online. It may not quite qualify as "cheap," but it is cheap for a decent Bluetooth sports headphone. Read the full review of the Plantronics BackBeat Fit.
Plantronics BackBeat Go 2
We liked Plantronics' earbud-style BackBeat Go at around $100 when it first came out. But you can now get it for closer to $70, £60 or AU$130 (with charging case). It's not really designed for running, but it works just fine for lighter workouts at the gym. Read the full review of the Plantronics BackBeat Go 2 + Charging Case.