Would and have. But the price has to be right.
All of these I own(ed) on DVD....
Band Of Brothers (Circa £15 IIRC)
Matrix Trilogy (£12.99)
In no particular order. Dirty Harry, Signs, Master & Commander: The Far Side Of The World, North By North-West, Leon, The Bourne Trilogy (Christmas pressie, cost my Sister £17ish I think), some others I can't recall just now. But pretty much all bought as part of a '3 for 2' or '2 for £20' or similar.
In fact, like the_lhc, I think the films I've bought on BD having never owned them before is a shorter list.
Kung Fu Hustle, Knowing, Transformers 2, Apocalypto, District 9, Anvil, Burn After Reading,