When a sender posts a delivery request we suggest a price for them to list it for. This price is based on previous successful deliveries of a similar size and distance, and should, therefore, be a fair price for both parties.
You are, however, free to price your offer as you see fit, but keep in mind that offers that are significantly higher than the price listed on the delivery request are unlikely to be accepted.
Some delivery requests might be priced lower than our suggestion. This normally happens if the sender is not in a rush with getting the item delivered or only is interested in buy an item if the delivery cost is reasonable enough and therefore can leave the request active until the right offer comes along. You can in these instances, of course, offer to help at a higher price to see if that works for the sender - in many instances we see such offers get accepted.