Only 18.000L$ and L$1762/week tier. Parcel has 937 prims allowance. Tiers can be paid via Paypal or with L$ in-world at the Tier Terminals. No premium account required!
The Island is owned by Fantasyland who owns ~200 Islands in SL and has a very good reputation for customer support and service.
slurl:
http://slurl.com/secondlife/Caribbean%20Crystal/234/36/22
