They could be using YaCy, setup their own infra and provide premium access to fast and more reliable YaCy results. That would at least make them a competitor an

They could be using YaCy, setup their own infra and provide premium access to fast and more reliable YaCy results. That would at least make them a competitor and not just a Bing UI. I mean, sure, it's cheaper, but it doesn't really set them apart from any other Bing UI. Actually running something they own, especially something opensource and federated, would distinguish them and warrant whatever fee they deem necessary.