How do you estimate design costs for consumer electronics products?

We’re a prototype manufacturer in China. We can estimate the cost and production of enclosures and mechanical parts. But lately we’ve received some clients' inquiries asking for the cost of a consumer electronics product (such as smartwatches, toothbrushes) from concept to a functional prototype.

That could include industrial and mechanical design, electronic component selection, PCB design, firmware, assembly, and testing. We’re familiar with the physical prototype manufacturing costs, but we don’t have ideas for the industrial design, drawings, and electronic components.

For those who have developed or commissioned a consumer electronics product, how do you usually break down and estimate these development costs?