A cost-plus basis for a contract about work to be done is one in which the buyer agrees to pay the seller or contractor all the cost plus a profit.
All vessels were to be built on a cost-plus basis.
...cost-plus contracts.
cost-plus in British English
noun
a.
a method of establishing a selling price in which an agreed percentage is added to the cost price to cover profit
b.
(as modifier)
cost-plus pricing
cost-plus in American English
(ˈkɔstˈplʌs)
US
adjective
with the price for goods or services set at the cost of materials, labor, etc. plus a specified percentage or amount of profit, as in some government contracts with industry