【Price】 ,  【charge】 ,  【cost】 ,  【expense】  can mean what is given or asked in payment for a thing or for its use, or for services.

【Price】  and  【charge】  in their ordinary nontechnical use commonly designate what is asked or demanded in the case of  【price】 , especially for goods or commodities; in the case of  【charge】 , especially for services.

In economics, however,  【price】 does not necessarily refer to a fixed sum of money asked by a seller, but to the quantity or number of units of one thing exchangeable in barter or sale for another thing.

【Charge】 , especially in accounting, also applies to what is imposed on one as a financial burden.

【Cost】  and  【expense】  in their ordinary nontechnical use apply to what is given or surrendered for something—  【cost】  often implying somewhat specifically the payment of the 【price】 asked and  【expense】 often designating the aggregate amount actually disbursed for something.

But  【cost】  sometimes replaces  【price】  with, however, a difference in connotation. Since  【cost】  applies to whatever must be given or sacrificed to obtain something, to produce something, or to attain some end whether it be money, labor, or lives or whether it is actually given or sacrificed, it, when replacing  【price】 , tends to suggest what will be taken or accepted from one in exchange rather than what the item is worth.

【Expense】 also may denote expenditure especially but not only of money.