I don't see the GP4000 on conti's website any more, so I'm assuming they've officially been replaced by the GP5K. I don't know whether Conti still has GP4K inventory, or if what we're seeing is distributor/retailer leftover inventory. I'd think that if Conti still had inventory they'd still have it on their website, but whadda I know?
These were being sold by an individual.