The person with less money should not have to spend more to avoid embarrassment.

Group habits often make the cheap option the visible one. Splitting the bill evenly, chipping in for a gift, defaulting to the nicer place: each of these quietly charges a premium to anyone who would have to say something to opt out. The premium is not the money; it is the choice between overspending and announcing your situation to the table. Most people pay rather than announce, and nobody notices it happening.

When you arrange something, build in a way to participate less expensively that requires no explanation. Suggest paying for what each person ordered. Offer the low-cost option first, so choosing it says nothing about anyone.