It is the price of blank discs which has stopped me buying a Blu-Ray burner for the PC. The actual drivers are down to under £200 now and quite affordable, but with each blank disc cost quite a lot it isn't worth it currently. Dual Layer DVDs can hold over 9GB so they are fine for the moment, and have dropped in price recently to under £1 each.
I do however agree that HD does look a lot better than SD, and the difference between SD DVD and HD BR is very noticeable. However, I know many of the less popular films have just been upscaled for the format, so there is no point buying those as a decent DVD player with upscale and HDMI looks good as it is. But for the big films like Avatar, Star Wars, Alien, T2 etc BR is definitely the format to have them on.
I do however have a decent setup with Sony 5.1 DTS receiver and Eltax home cinema speakers, plus nice large sub, so the only thing missing is actually the BR player. I might get one later this year.