My developer quoted me $5k to transfer my orders and customers, total about 250k entities with a 10 day to deliver project. I have CSCart and migrating over to Magento 2.
I found cart2cart and got all of them done within 2 hours and did it myself. It was as simple as mapping a few fields from your source destination to your target destination and click submit.
Project was successfully done ahead of schedule and most importantly i saved over 80%. Would recommend to anyone doing a cart migration project