Why have the prices of Marantz and Sansui speakers have gone up so much? Whyyyy???

Hipsters.

Some of the receivers etc  from the 1970s are collectible now people are buying the speakers and TT etc to get complete systems. This in no way obsoletes any audiophiles gear selection so just relax. It doesn't mean that they are inferior to you they are just collecting as humanity has done for ages.

I understand, but if im putting a vintage system together you can be sure the speakers will be worthy of listening to and enjoying.

I dont see realistic speakers going up crazily in value like marantz and sansui but willing to bet the realistic sound alot better

I don't understand the fascination with those antique speakers. I've certainly never heard any that hold a candle to today's mid-level products. If you get inside those things and replaced those ancient caps and resistors they start sounding more modern. Same goes for those antique amps and receivers. Stereophile did a comparison of some price equivalent speakers from way back and some modern speakers. It wasn't even a contest.