Mauritius: HB/FB or AI

Good morning everyone!

I was planning to go to Mauritius by the end of October 2018. I had a nice deal at 1350Eur for Riu Creole AI but that is sold out. Now the same option costs 1693Eur/person which is out of my budget for this year as I'd like to dive and do tours in there, which would be more than 2000eur in total.

My question is: is it worth to go AI in Mauritius? We are going as a couple, we want to spend at least 2/3 days in the beach doing nothing else, but then explore the islands the rest of the week. We were aiming at Le morne, but now i'm more into Grand Baie.

Should I go HB? Are there cheap local restaurants in the area? What prices should I expect for a Beer in the hotel/outside the hotel? I've been in Maldives, and by the time we were in HB and we payed a LOT in the end (1 bottle of water = 8 $ !!!!!!! ) so I'm afraid that would be the same in MRU.

Also, what are the best beaches to be at during October?

Thanks in advance