A commercial document issued by a seller to the buyer, indicating the products, quantities, and agreed prices for products or services the seller has provided

Installment sale is selling property and receiving the sales price over a series of payments, instead of all at once at the close of the

In large quantities (source: wordreference.com)

Door to door parcel delivery service offered by companies.

A type of negotiation in which the buyer and seller of a good or service dispute the price which will be paid and the exact

To sell goods informally in public places (source: http://dictionary.cambridge.org/dictionary/british/hawk_3)