The main reason for the price fluctuation between different mechanic tool kits is the number of parts included in the kit, though the brand and the type of tools also factor into the price. If you are looking at a Craftsman tool set with more than 100 pieces, then it’s likely to be more expensive than a DeWalt mechanic tool kit with just 10 pieces, unless the 10 pieces happen to be specialized tools. In which case, the DeWalt mechanics tool kit may be the premium option.