I use a Classified 3.0. Buy It Now & multi object sell is often used in my sites. The program is, however, a lack of which I have not found a solution. There is not a place where you can write the number of pieces, so PayPal will bill only for one piece. Often, however, the situation is that there is for example 10 pieces for sale and the buyer wants to buy 4 pieces at one time. So, the price of 4 pcs + shipping costs should move to a PayPal invoice for the buyer to pay for the entire order at once.
Would it be a difficult thing to change its like that?