Product cost estimation in early design stage puzzles researchers for long-time. A new product cost estimation model is proposed, which is applicable for few estimating samples and product information in early design stage. Similarity between the estimating product and the samples are calculated by model of Euclidean distance. Both of utilization ratio of estimating samples and reliability of estimation result are improved based on samples’ sequencing for effect of product cost. The cost estimation model is applied in design of claw of brake disc. The estimation result indicates that the presented model can be used for condition of few estimating samples and product information in early design phase.