The right amount of cash depends on your budget, not on the size of the show. Decide what you are willing to spend before you enter, then bring enough cash for planned purchases, admission, parking, and a modest buffer. Many dealers accept cards or apps, but venue connectivity can fail and some sellers prefer cash for smaller deals. Use the events calendar to check show size and fees, then build your budget around specific goals rather than impulse.
Keep cash divided and out of sight. Do not flash a large roll at a table, and do not carry more than you can comfortably lose or manage. For higher-value purchases, ask whether the dealer accepts a safer payment method and provides a receipt. The first card show prep guide covers budgeting and logistics. Nearby card shops can be useful after the show if you decide not to spend all your cash on a pressured floor purchase.