We need a word that means almost the same thing as sellout (in the sense of "a person who compromises their principles for financial gain"), but conveys the idea that the problem is not selling out, but selling out for too low of a price. We all have to make trade-offs; there isn't any one principle that takes lexical priority over every other valuable thing in life: sometimes it makes sense to compromise your ideals in exchange for money or power or fame or fitting in.

But you could at least haggle!