The most you can pay for each card and still clear your target margin. Decide the limit before you shop — evaluating a listing after you've found it is how you talk yourself into a bad buy.
Pay Up To hits your 30% margin. Break Even is where profit hits zero — the space between them is your negotiating room, not a target.
This assumes every card comes back PSA 10, which won't happen. Real submissions spread across grades, and the value gap between a 9 and a 10 is often several times the gap between an 8 and a 9. Once Performance has your actual grade rates from enough submissions, weight these limits by what you really hit — and until then, treat PSA 8 as a deliberately conservative floor rather than a forecast.