[TheRealPomax]

It feels like you never looked at https://www.uspto.gov/web/offices/pac/mpep/s2215.html and it might be worth giving that a quick read before pulling a number out of thin air.

Yes, it costs money to get a patent invalidated based on prior art. But: an amount that even a single person who stands to actually gain from having a patent overturned should have no problem with. You're asking the USPO to spend time redoing work, literally halting any other patent work they could be doing instead. So it's not a trivial amount, but it's also hardly a prohibitive amount if you actually want a specific patent revoked.

[rasz]

https://arapackelaw.com/inter-partes-review/ipr-better-inval...

The AIPLA Report of the Economic Survey for 2017 notes that the typical patent infringement suit with less than $1 million at stake costs on average costs more than $600,000 dollars, while the typical patent infringement suit with between $1-10 million at stake costs on average nearly $1.5 million to litigate.

https://blueironip.com/what-are-the-costs-to-enforce-or-defe...

Costs for IPR or Post-Grant Review (approximate mean):

    Through filing petition: $120,000.
    Through end of motion practice: $300,000.
    Through PTAB hearing: $400,000.
    Through appeal: $600,000

[retcon]

Arithmetic mean isn't a useful guide for litigation. Take the $600,000 as your entry price and you are on the right track.