It is not up-front, it is per-semester. I think there is a relatively small application fee ( $50? ). Once in, it is ~$500 per course plus ~$300 per semester. So if you take one course a semester it is ~$800 for the semester, if you take two courses per semester it is ~$1300. The program requires 10 courses to graduate. For some classes you will need to buy a book or two, but many do not have any required textbook, or use a book available online.

You pay at the beginning of each semester for the classes you'll take during that semester. It's not a lump sum.

So as a rough estimate if there would be 4 semesters , I would be spending roghly 1750 USD per semester . I know there would be some deviation. But is that a fair guess and financial planning ?

Here's the cost breakdown per course and semester: https://www.omscs.gatech.edu/program-info/cost-payment-sched...