Blu-ray On PC With HDTV

[Wadeyboy]

I've just bought a new computer and an HDTV to put the computer through, rather than a monitor. I was thinking of buying a Blu Ray drive to play movies, games, etc. My brother set it all up for me as I'm disabled but connected the PC to the HDTV with a VGA lead. I was told to be able to display Blu Ray movies in 1080 high def, I needed an HDMI to DVI lead. However, my brother said that an HDMI lead would be "a waste of money as you would barely notice the difference." Is he right? PC World wanted £75 for an HDMI lead and this is a lot of money to pay if I would "barely notice the difference." I would be grateful for any advice.