The designer will typically use one of a selection of thousands of different types of software on the market today to create your product.
Each software typically perform the same actions but in general software is chosen dependent on the industry the designer is trained in.
There are 3 levels of software to choose from, the high end, the mid end and the low end and they are priced accordingly from $500 to $20,000 for each license. The reason for the different software and price levels is to do with the functions offered by each software. High end industries such as automotive and aviation typically need more functions than mid or low end software can offer.
Most software used by product designers will need to pay an annual maintenance fee, so the higher the level the higher the fee. This cost in turn could result in an expensive design fee charged to you.
Generally for a new product design using mid level software is ample and keeps the design cost to a minimum.
You don’t need to concern yourself too much about which software the designer uses but its recommended you see at least 3 design companies to compare quotes against.
You designer should understand manufacturing processes, if he doesnt then maybe consider changing designer. Ensure you understand the designers history and examples of past designs is a must.