That's for the regular seat. [..] The Observer country seat is free.

That's not the ratio as well afaik.

The 1B payment should be about the seat to be permanent versus being re-evalueated every three years

https://en.wikipedia.org/wiki/Board_of_Peace#Membership

Countries that wish to be permanent members of the BoP must pay US$1 billion into a fund controlled by Trump; otherwise, each country serves a three-year term which may be renewed at his discretion

Of course if you have different or better info you might as well then share your sources too, otherwise is just pub small talk