I live in Italy and I get tired of seeing things here that look Italian but are made in China. So when I am visiting another country I strive to find something made by a local artisan. There is such a shop just at the exit of the ruins, turn right and walk to the first shop.
See photos below of the Greek man who owns and works there.
His shop is high quality, and he takes great pride over the things he has there.
What to buy: I was looking for something in porcelin, with a Greek design. There are lots of them here.
What to pay: Under ten euros.
Between the area of Ancient Corinth and the new city centre of Corinth, you'll find a very nice pottery shop at the northside of the road. You'll find lots of sizes, shapes and scenes of the vases and plates inside and the best thing: they are all handpainted.
The lady that runs the shop is always busy painting the pottery and is well willing to tell you about the scene it shows. Prices are not more expensive then the mass produced ones you find in Athens. The objects are all signed by the lady "Hazia Starfa" and are a great souvenir of your visit to Corinth...