Air France launched its Christmas Sale for flights to Asia, Africa and Caribbean.
Travel dates: 15.12.2016-30.06.2017
I searched from closest European hub (Milan) and I found a flight from Milan Linate to Reunion for EUR 511/ USD 566 .
For accommodation I recommend you to search on HotelsCombined as it aggregates all booking portals including Booking. You can find hotel reviews on Tripadvisor which is also great for searching best places to visit.
Hostelworld offers perfect budget accommodation for students, backpackers and low cost travelers.
If you want to stay with a local, you should rent a room, apartment or house on Airbnb. When you travel on Airbnb, you will get €18 in travel credit as my referral.
I suggest to rent a car from RentalCars if you want to drive around.