Interesting poll. In the 2000s made a list of movies I wished to have in DVD because that was, imho, THE long-lasting, digital, high definition, archival medium. It was mostly 80s movies. Then I lost interest and never bought all the movies in the list. I have the first 6 Star Trek movies.
I almost bought a bluray because of TRON, but nah.
Blu-ray is like crack. Once you've seen one good transfer, you're hooked!
I dont do drugs either . But DVD resolution is fine for me. Any better and you start to see pimples in actors and bad things in the special effects. If not, everything has to be upscaled, remastered, retouched or re-something.
Also, nothing is cheap. I'd have to buy a new TV too. IF they would give a very good rebate for the old DVDs, I'd consider.
All above is only IMHO, of course.