Book flights, pay bills, bring phones from abroad, order on sale days with your card? List your charge on the exact thing — a route, a board, a phone, a store — and buyers compare it with everyone else's. You're paid what it cost plus your charge when they confirm the bill.
Anything else — tutoring, ITR filing, a trip planned — with your rates, on a page of its own. Requests in your categories appear below: the first to claim one takes the job.
First to claim locks the job — no one else can take it after.