This doesn’t parse as disagreement—Eukaryote only said that asker should be willing to pay a nonzero amount, not that a nonzero payment should actually happen.
So, according to my read of Eukaryote (and also according to me):
“My cheerful price is $0” / “great, will you do it for $0?”—fine.
“My cheerful price is $0.01” / “oh, hm, I don’t actually want to pay a cent for it”—not cool.
“Honestly I’d have done it for free as a favor, but since you ask my cheerful price is $5” / “oh, okay, will you do it for free?”—not cool.
(Edited to add:) “Honestly I’d have done it for free as a favor, but since you ask my cheerful price is $5” / “hm, I don’t want to pay $5, but will you do it for $2?”—fine.
This doesn’t parse as disagreement—Eukaryote only said that asker should be willing to pay a nonzero amount, not that a nonzero payment should actually happen.
So, according to my read of Eukaryote (and also according to me):
“My cheerful price is $0” / “great, will you do it for $0?”—fine.
“My cheerful price is $0.01” / “oh, hm, I don’t actually want to pay a cent for it”—not cool.
“Honestly I’d have done it for free as a favor, but since you ask my cheerful price is $5” / “oh, okay, will you do it for free?”—not cool.
(Edited to add:) “Honestly I’d have done it for free as a favor, but since you ask my cheerful price is $5” / “hm, I don’t want to pay $5, but will you do it for $2?”—fine.