Would appreciate your suggestions. For examples, would like to spend under 20€ per primo piatto.
I get the best food tips from blogs--a google search will turn up a ton if you don't get a list that satisfies you here.
One of my favorite meals in Matera was at Dalla Padella alla Brace--just the appetizer platter would have fed an army, but it was delicious in addition to being a great bargain.
Another meal I made a point to repeat on my second visit to Matera was at the park headquarters across the gorge, which sells traditional food like bean soup. It appears it is temporarily closed for restoration: https://www.ceamatera.it/news/english/