Here’s Bauer’s rundown on the cost of building a rock-bottom, entry-level Catfish:

The rock-bottom DIY builder could make the car for less than $20,000, with the main expenses as follows:

 Kit price:                        $13,900 

Donor car                          1,000                  

wheels and tires                    500

paint or vinyl wrap              1,000                             

 miscellaneous mechanicals  1,000

The DIY buyer can also sell off the parts he doesn't use, such as the complete shell to a Spec Miata racer, doors, glass, HVAC, lights, interior, top/hard top, wheels/tires, shocks/springs, and any extras that have found their way onto the Miata.  $500 or more could be realized, making an all-in price of $17K possible.