Start from the plate, not the market
Cost one plate properly: protein, starch, sides, packaging, disposables. Then add the things people forget — gas, ice, the generator, transport to a venue on the mainland at 4pm.
Only then look at what other people charge. If your honest number is above the market, the answer is a different menu, not a thinner margin.
Why the count is the whole risk
A client confirms 500. On the day, 700 arrive. The extra 200 plates come out of your pocket unless you agreed in advance what happens.
The fix is arithmetic, not goodwill: state the confirmed number, a buffer you will cover at no charge (5–10% is normal), and a clear rate per head beyond it. Put it in the quote your client accepts, not in a voice note.
Deposits that actually protect you
A deposit that does not cover your food cost is not a deposit, it is a gesture. For a December date, ask for enough to buy the materials, and hold the balance to before the event rather than on the day at the venue gate.
The additions problem
“Just add small small” is how a profitable job becomes a break-even one. Every addition should be a small approval with a number on it, sent and accepted before it is cooked.