Exposure Maxx D mk12 2nd hand price?

Hi all.
So looking to replace a Hope R4 light system (seperate battery pack) to an all in one system.
I'm now on a Giant Defy, mainly commuting 7 miles each way on & off road but rough tarmac some dark patches and a bit twisty turny dogs & dog walkers etc through parks /shared space and NCN etc.
I'm in discussions with a seller of an Exposure Maxx D mk12 3400 Luman, they were wanting £192 and now offering £150 is it a good deal?
Thanks