There is certainly no cold or rainy weather in Punta Cana during autumn. According to current forecast you can expect wonderful 31°C sunny weather in November. Combined with white beaches, palms and pristine water it makes it a great holiday.
The flights are operated by Air France on a cheapest Economy Light fares which include only 1 free cabin baggage. Purchasing a checked bag or a custom seat selection is optionable and for an additional fee (bag £45, seat selection from £9).
Tickets to this destination are usually in range between £560 – £680 so it is certainly a good deal.