* Type of car: Basic Hot Wheels can be found for under $1 each, while premium, collectible, or older models can cost upwards of $10, $20, or even hundreds of dollars each.
* Where you buy them: A big box store like Walmart will likely have lower prices than a specialty toy store or online auction site.
* Condition: Mint condition, unopened cars will cost more than used ones.
Therefore, it's impossible to give a precise answer. The total cost could range from $40 (40 x $1) to several hundred or even thousands of dollars depending on the factors mentioned above.
