Thank FvM, I think I have used the wrong words here. Altera has the following on their website:
ByteBlaster II Download Cable
USB-Blaster Download Cable
EthernetBlaster II Download Cable
I have a laptop which lacks parallel port so the information you have provided will not directly benefit me at this time. What I am looking for is the USB-Blaster II. I made a mistake when I said Byte Blaster II in my previous post. For some reason I had in my head that the device I am looking for is "USB-ByteBlaster II" but it is clear to me that no device with this specific name exists. While the Altera website lists the 3 devices I have mentioned above. However, there is also a USB-Blaster II available. I have found a user guide of it.
This is the userguide for USB-Blaster I:
https://www.altera.com/content/dam/altera-www/global/en_US/pdfs/literature/ug/ug_usb_blstr.pdf
This is the userguide for USB-Blaster II:
https://www.altera.com/en_US/pdfs/literature/ug/ug_usb_blstr_II_cable.pdf
While the Altera website has the userguide for the USB-Blaster II, I can only buy USB-Blaster I through it. Since, the userguide of the latter device is dated October 2014, I would expect it to be available in the market. However, it does not seem to be the case as it is not available for sale on any website I have seen yet.
By the way, the Altera USB-Blaster I costs 300$ on the Altera website, this would be about 200£. Then, there is a similar looking device from Terasic called "Terasic Blaster". It is identical to the Altera USB Blaster but costs 50$ (about 33£) instead. Then you have mentioned "clones" of the USB blaster that cost even cheaper. I am confused, how can a product which does the same thing have so many forms and such varying price range?