Emphasis added by me:
Minority Group: ‑2 on all reaction rolls.*
Savage: -2 on reaction rolls and -4 on skill rolls when buying or selling goods, finding backers, or engaging in similar negotiations, and a 6 or less chance of being denied entry to town.*
* Except from others of your own kind, in both cases.
In
GURPS terms, Minority Group amounts to Reputation -2 all the time, while Savage amounts to Reputation -2 among potential business partners,
plus Incompetence at business,
plus an added bit about not being welcome in town.
Minority Group means you're disliked because while you're from a true culture, it's one nobody likes because it's seen as too distant, different, and/or dangerous. Savage means you're regarded as belonging to a barely sapient monster race that doesn't have a culture. In the former case, cultural contrasts lead to problems just about everywhere, not just in business; even as a mercenary, you're not trusted because maybe you're really an advance barbarian scout spying on the state that hired you. In the latter, you're seen largely as a beast, not savvy enough to be trusted around civilized stuff like contracts and deals, but nobody is going to mind much if – like a guard animal or a warhorse – you're hanging around as useful muscle.