How far has speaker technology come?


Currently I am using my dad's old Wharfedale E-90s. From what I get from talking to him about it, they retailed for somewhere in the neighborhood of $2000 dollars back in the 80's when he bought them. I guess if you want to scale the price back then to todays money, taking into account inflation and what not, they are probably the equivalent of an $8000 pair of speakers in todays market, at least as far as dollar value is concerned. But anyways, does anyone have any idea or opinion as to what I improvements I should expect to hear if I were to buy a more "modern" speaker which retailed for about $8000 new? Could I expect the quality to be substantially better, seeing how these speakers are over 20yrs old? Can a dollar today buy more speaker "bang" for the buck, or has it stayed the same over the past 2 decades? Has the area truly advanced, or is it just running around in circles? Is the progression as obvious as digital technology? My dad is also looking to purchase a newer speaker for about $2000 used. For that amount of money, could he expect to find a speaker "better" than the E-90s? I've asked retailers in my area, but their opinions are inherently biased, so I want a "real" opinion. I do understand that the word "better" is subjective to interpretation, but I am sure there has to be some widely acceptable basis for evaluation. Clarity, imaging, detail, presentation.... all those good things.

Thanks in advance
krazeeyk
Mostly the cost reduction.
Modern speakers producers try to sell you a cheaper staff like a know-how!
Cheap ferritic magnets - instead of of more expansive and stronger alnico magnets.
Cheap small plastic cones driver - instead of more expansive big paper cones. 
Narrow boxes have a gap in upper bass-low midrange frequency regione and lower sensitivity.