I buy them mostly second hand (there are a few reputable online shops for that over here), the price difference between DVD and BD is small (like 5 instead of 7€) But yeah, you are probably right, I remember when every parent bought a DVD player and they all threw out their VCS and just a few years later Bluray was the new thing and they just refused to do the same thing again :D these people are probably still using their dvd players from back then