Not exactly. Non-recurring engineering is often cost plus. You simply can't scope that out very well. Purchasing more units of an already developed item is gene

Not exactly. Non-recurring engineering is often cost plus. You simply can't scope that out very well. Purchasing more units of an already developed item is generally fixed price. However, even with cost plus there are incentives to come in faster/better/cheaper. If you run a company and have the choice between '1 project scheduled for 18 months, stretched to 2 years and collect the extra' or '2 projects scheduled for 18 months, each finished in a year, and collect all the extra bonuses', you typically choose the second plan.