Simply keep the item in your trade then complete the trade. You can do this by hitting the trade in button at the bottom of the trade page. Remember you have to have a minimum of $15 value in your trade to redeem the offer. You can always remove individual items from your trade if you don't accept the offer price. Just hit the minus button next to the item and it will be removed.

World of Books Inc. doing business as Ziffit, with offices at Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware (USA) 19801