Dee
I usually take suncream with me but ran out of F25 last year and bought some from the Elephant shop - it was Boots Soltan, exactly the same as I use.
It was halfway into our holiday so I'd got a base tan, I didn't spend any longer in the sun than normal, it wasn't any hotter than normal - and I burned!
I'll never rely on suncream bought abroad again.
Surely if you're thinking about saving weight for souvenirs, it's not so much what you take out but bring back.....
If you can get your toiletries in your case on the way out and use or throw them away, you will definitely have space in your case for souvenirs.
I also take 6 or so paperback books in our case, all within our 20kg each, so I know that, after throwing shower gel & suncream away and leaving books in the hotel, I've got enough spare weight for a few handbags.
You could take older beach towels and throw/give them away at the end of your holiday. Or even buy them in Goa and leave them.
Same for old sandals & clothes.
Sorry, I know this is now going