They probably will go higher and higher as people keep parting out their speakers making them more rare/collectible.
I almost bought a pair of mint Betas a few years ago from the original owner for $4,200 but decided not to because my room is too small for them.
I have to laugh at the epsilons on the bay that are $10,500 they are missing the felt damper on one front tweeter and I think they played around with the control woofers to get them working, my epsilons are in way better shape, maybe I should put them up for sale and ask $12,500 for them Lol,
When people see sellers trying to sell their infinity speakers at such high prices they think that must be what the speakers are worth so they put their speakers up for sale at those high prices too, It's like a chain reaction now everyone is asking ridiculously high prices for their infinity's but nothing sells.
Did you see the Kappa 8's from Japan on the bay for $5,700 Lol, I bought my K8's new for $1,400 plus tax.