Viewed another way, you got an unbelievable bargain. In the realm of passive speakers, which is still the norm in home systems, their design-engineering equates to products selling in 5 figures. I know factually that multiple other manufacturers would claim $15,000 as cabinet value alone.
I understand the desire to buy stuff as cheap as possible. But, I also encourage you to consider the intrinsic value of the goods. Pick a dozen brands / products at $20K and compare your new 3.6s toe to toe. I bet you'll be thrilled.