> When everyone, even poor people, have an extra (say) $10k, basic cost of living could go up $10k because that's what the market will bear.
If you assume a totally monopolistic marketplace (so that there is no competition to drive down prices but instead there is unlimited capacity to extract monopoly rents), sure. In a marketplace with any kind of competition you'd expect some increase in each the market clearing price and the market clearing quantity of each of the goods that would be purchased by the people who end up with a greater net income after the policy change.
If you assume a totally monopolistic marketplace (so that there is no competition to drive down prices but instead there is unlimited capacity to extract monopoly rents), sure. In a marketplace with any kind of competition you'd expect some increase in each the market clearing price and the market clearing quantity of each of the goods that would be purchased by the people who end up with a greater net income after the policy change.