We've stayed in the Owner's Villa many times. Although the patio is not really private in the sense that people can see what you're doing, the resort is so small that it doesn't really matter. The whole place can only hold around 35 people. We've had no issues puffing on the patio any time. We'll be staying there again this December. It will not be in your budget though, just the room itself will be double your budget (depending on the time of the year), not including food and drinks. There are no on site facilities at Nirvana, but the White Sands is right next door with a great bar and Tony's hut is very close too.
Idle Awhile is nice, but the suites won't be in your budget, maybe the rooms, but don't get garden view rooms if you can avoid it, they are at back and can be noisy from the kitchen back there.
'