"Can you please confirm that I will get this passive radiator model from the site you have mentioned.
PR18-1600 -- $100"
Absolutely NOT.
What I said was:
"Contact these people about a custom PR. I'm guessing a full-cone 18 of about 300grams."
They can evaluate your driver and they MAY be able to build one for your application. Their normal price on an 18" PR is $129, I would expect a custom plus design to be more.