When you're actually charged
Checking out and being charged are two different moments. What happens in between depends on whether the order is pickup or delivery.
Checkout only puts a hold on your card
Checking out authorizes your card for the order total. Nothing is captured yet — the amount is only held, and it's released if the order never goes ahead.
A pickup order is charged when the seller marks it ready
For pickup, the capture happens on the seller's side: when they tap "Mark ready for pickup," that's the action that charges you. It happens before you actually collect anything.
A delivery order is charged when you confirm it arrived
For delivery, the capture is on your side instead: nothing is charged until you tap "Confirm delivery received" once it shows up. That same action is what pays the seller.
There's no separate buyer fee today
The order total you're charged is the subtotal of what you ordered. EZH's commission comes out of what the seller receives, not something added on top of what you pay.