Second hand batteries for MP?

Having recently bought an MP on Ebay - done well I hope, looks immaculate and got it for a half-decent price - I was looking about for a third battery as it came with only two.
Found second-hand batteries for around the £45-£50 mark on, which appears to be a source of used camera gear. I wonder how they come by them, but anyway thought I’d ask if any other GADC members have bought these and found them OK?


I have bought a couple of batteries for a Crystslsky monitor from them and they were like new. No problems at all. They are a well established company.