Given the time you actually have I am not sure how you have time to see more than Matera ???
15 min. drive outside of Matera there the Crypt of the Original Sin ; which is a preserved rock church with frescos ; can buy tickets online

Otherwise....
Pietrapertosa and Castelmezzano are in Basilicata (2 very pretty mountain towns and there is a zip line type ride you can go on between the ridge connecting the 2 towns ; think it is called Flight of The Angels or similar).

Paestum (famous historical Greek temples in excellent condition). Don't think this is in Basilicata technically but on your drive it may not be far off your route. There is also a famous Mozzarella farm in this town many will combine that with the ruins in Paestum.

Have not been to Craco as mentioned in the post above but it does look like a cool place to stop. Though if going to Matera not sure you need to see both?