for 2007 >
Winvian - from $1450 (all detached villas)
The Point - from $1250 (villa from $2600)
Twin Farms - from $1100 (villas from $1750)
Blackberry Farm - from $745 (villas from $1340, 1-3BR)

so besides room/villa, the difference really comes down to
- free F&B and activities
- additional costs for other activities, spa, and premium beverages

(note the first 3 are top 4 by rate in the US, after the Mansion in Vegas)