Goa will be very expensive. like a lot expensive than pondicherry but then what happens in pondicherry you'll get it in goa but what happens in south goa and west goa you wont find it anywhere in pondicherry
Both the destinations are unique and comparing the two is not justified. Pondicherry is a calm and soothing place with french colonial streets and Goa is somehow a destination where you just stay chill relax have good time You actually can go to Goa and relax at your holiday - the beaches, parties, palm trees and wine and sunset
If you are looking for partying or chilling then Goa is the perfect for it.
If you are looking for a mix experience then Pondicherry is perfect. Pondicherry has beaches, Ashram, French colony, Food culture, Churches etc.
You can also visit "Auroville" which is the unique & peaceful place, also known for betterment of society.
I think Pondicherry is a good choice... as Goa is frequently visited by travellers and there are too many tourists there right now ever since the borders have been opened... Pondicherry should be relatively calmer
Goa is frequently visited and would be the first choice for many. But Pondicherry has it's own unique vibe and experience, very much different than Goa.
And most people have visited Goa, Why not give Pondicherry a shot for a change.