Why are so many Infinity IRS beta systems for sale the past year ?

Speaking of aging like this response Tomic is 💯 right a very rewarding set of speakers IF you get the right gear to compliment them , otherwise they tell tales on inferior or gear not suitable. They may be $10K for the speakers now same as the original price. But if you can get 50K of carefully chosen gear to run them then you get a system that would cost well over 200K to get close , I’ve made listening  rooms for both Our best Audiophile stores in Sydney  & I’ve had the chance to listen to some top end gear I wouldn’t swap my betas for some 250K speakers I listened to running the same amps . I was lucky to have had someone who tried so many combos with these speakers to get my setup near perfect every step up was amazing leap. They are extremely accurate & a downside will show any harshness in any components in the chain. But get it right 😁

Well, the Infinity ribbon drivers have their own unique sound but after 40 years of listening I moved on to something else. 

As above, the IRS System takes a large to very large listening space plus high powered gear to fully compliment (drive) properly.  To my knowledge, there is only 1 place in the U.S. that can fully service Vintage Infinity in Orange County, CA.

Imagine to cost of packing/shipping if One lives outside of the state of California.

Happy Listening!

The short answer is they are awful loudspeakers. They are incapable of imaging correctly just like the Nearfield Pipedreams. They can go very loud and cast a "big" impressive sound but that is about it. They are very big background music speakers. You are much better off with Magneplanar 20.7s or bigger Sound Labs. Both require large subwoofer systems.

As you mentioned "' I was lucky to have had someone who tried so many combos with these speakers to get my setup near perfect every step up was amazing leap.''

What are these combos, which you are using with this speakers IRS Betas. I am also a proud owner of Infinity Betas