I was searching for E-M5 grips and have noticed that Amazon.co.uk (sold by Amazon and NOT a third party) currently have the HLD-8 at the same price as the 8G (which is just the landscape grip).
http://www.amazon.co.uk/Olympus-HLD-8-Power-Battery-Holder/dp/B00SMPLI60/
I have also run this through Flubit and it came back with a price of £119.52
http://www.amazon.co.uk/Olympus-HLD-8-Power-Battery-Holder/dp/B00SMPLI60/
I have also run this through Flubit and it came back with a price of £119.52