My internal definition of guilt is screwed up because I have OCD. This is why I am so keen on defining guilt carefully.

What I am describing above is just discomfort. Unless the parent poster deliberately sought to underpay the person, they should have no guilt merely from that scenario. Discomfort is real enough.

Guilt might attach if they do not or choose not to act on that discomfort, or if the person is materially disadvantaged by not doing the ongoing work, or if a promise of better pay/longer employment was attached to asking for that work to be done at a low pay.