Lumeinshin
I don't know. Lainchan's server costs 55$ per month, so that might give an idea of the total cost of heyuri.
Merulox
Again I don't know. It might as well be fake.
Taka
The nanosphere is pretty much dead anyway. It is just too easy to host things on tor/i2p nowadays. As a result most of those image boards are now long dead and to be honest I think it's better that way.
EDIT: Somehow I can't @ someone anymore.