Costed is a word. There may be some confusion about this because in American English, the past tense of the verb cost is the irregular cost, as in Things cost a lot less back then. However, in some dialects of English, costed is the preferred past tense of cost.

Additionally, costed is the preferred past tense form when it is used to describe the act of determining the price or worth of an item, as in We costed the business and were prepared to buy it. This use is much more rare, however.

It’s also used for the past tense of the phrasal verb cost out, meaning “to calculate the cost in advance,” as in Jeremy costed out all the projects for this year by February.

**What’s the past tense of cost?**

In American English, the past tense of the verb cost is usually the irregular cost, as in When I was growing up, a gallon of milk cost a dollar. However, in some dialects of English, costed is the preferred past tense of cost.

Additionally, costed is the preferred past tense form when it is used to describe the act of determining the price or worth of an item, as in The company costed the new electric trucks and was prepared to buy several. This use is much more rare, however.

Costed also used for the past tense of the phrasal verb cost out, meaning “to calculate the cost in advance,” as in We costed out the projects for this year and realized the company is in financial trouble.

With the exception of these situations, however, cost is most often used.

Did you mean accosted?