I recently watched “Brief history of the Wrong Earths” by Hardcore Sci-Fi, not many of these are well known so you could have so much more ammunition for fooling around like that with people.
“flat earth? Nah, it’s expanding bro! Oh wait actually it’s 9 hollow earths one in another!”
And remember! The high price tag attached to Concord had no influence on it’s success! People will gladly pay for stuff that is offered for free elsewhere!