Русско-англо-русский юридический словарь

purchase price - the price at which something is actually purchased (TheFreeDictionary)

Such an agreement may cover the purchase and sale of a business division, intellectual property, land or buildings. Besides a description of the assets and the purchase price, the agreement may also include relevant representations, warranties and covenants. (contracts.onecle.com)

A value-added tax (VAT) or also General Sales tax (GST) is a form of consumption tax. From the perspective of the buyer, it is a tax on the purchase price. From that of the seller, it is a tax only on the value added to a product, material, or service, from an accounting point of view, by this stage of its manufacture or distribution. The manufacturer remits to the government the difference between these two amounts, and retains the rest for themselves to offset the taxes they had previously paid on the inputs. (Wikipedia)

Articles 1346–49 of the civil code provide rules to govern the subject matter of a transaction. Subject matter of a transaction should be distinguished from the subject matter (or prestation) of an obligation and in turn from the subject matter of the prestation itself, which is the action or abstinence required of the obligor (to do, to give or to refrain). The subject matter of a transaction is, however, often identified by a kind of transposition with that of an obligation. The subject matter is thus the thing or activity on which the transaction is based. In a sale contract, for example, the subject matter is the thing sold and the purchase price; in a letting it is the flat rented and the rent paid for it; in a loan it is the money lent and then repaid; and in a delivery contract is it is the thing sent and the price paid for delivering it.

Subject matter is distinct from the object, which is the aim of the transaction. (Italian Private Law by Guido Alpa, Vincenzo Zeno-Zencovich)