The thing with 70’s speakers is the quality of the construction, the cabinets are usually solid wood or good quality multi layer ply with a thick veneer, the sheer size of the cabs, which is imperative for good bass response (unless using 4th,5th or 6th order reflex) and the high quality of the crossover components.
In comparison during the 80’s and 90’s the construction tended to focus on compact size and more styling to the detriment of the cabs and crossovers.
I use two pairs of 70’s MS’s and have used B&W DM2’s both of which cost me <200 a pair. the MS400 & MS700 have a superior sound quality to many speakers costing several 1000’s. A lot of this is due to the sheer size and weight of them.