Is it costed or cost?
The verb “cost” has two different past tense forms, depending on the meaning being used. The more common meaning, referring to the price that is paid for goods or services, is an irregular verb. The spelling remains the same as the infinitive—cost (e.g., “Andy was delighted that the watch repair had cost less than he feared”).
A less common meaning of “cost,” typically used only in British English, is “to give an estimate of price for work or a project.” When used in this way, it is a regular verb that adds “-ed” for the past tense and past participle (e.g., “Thankfully, the project had been carefully costed to cover exchange-rate fluctuations”).
The Quillbot Grammar Checker can help you make sure your spelling and grammar are correct.