I have seen a few KCOM branded ones on eBay recently around the £30 mark. I was going to pick one up to help diagnose a fault but I just used the Openreach modem instead. Seems a good bargain anyway, even more so if you need a G.fast modem.
I have skimmed your other thread about the vulnerability and I think it is disappointing that the FTP server has not been updated with the latest firmware since I have been checking that every now and again for months, as that's where I would expect it to be. I have requested the firmware so hopefully I will get that very soon. Thanks for bringing that to my attention.