Some companies have money and want to complete a project, and some developers can do the work and want to be compensated. The process by which the compensation is determined involves negotiation. That is a two-sided process. In none of the presented screenshots did the author actually propose what she thought was a fair compensation for the work. She suggests $20K may work but that is the moment to say what she thinks is fair or what would have been worth her time
A lot of people who do emulator work are not based in SF. Many are in other countries where $10K stretches a lot further. The actual offer is not really insulting if the company didn't know she was in such a high COL area.
In the case of GBA emulator work, there is some sort of market. For example, MVG wrote the emulator for the Shantae re-release and there's no reason to believe others can't do the same.
If the author straight up made a counter, we could judge the reasonableness accordingly. In absence, it seems like entitlement.