Be a Billionaire ... For a Week

FOR UPSCALE CONSUMERS WHO WANT TO sample the good life on a budget, part-time luxury is in. Time-shares have long been a popular way to vacation in Florida or the Caribbean. Now a host of new ventures offers shared use of elite playthings at a fraction of their usual cost.

ABOVE PAR Tour GCX members pay $6,250 for 10 four-player rounds at any of 14 exclusive U.S. golf courses--far less than the $50,000 initiation fee some clubs charge.

CARPOOLING Who needs to spend $200,000 on a fancy sports car? Exotic Car Share members pay $15,000 plus fees to drive a Ferrari for seven weeks a year. Rolls-Royces are available too.

GRAPE CHIC At the Napa Valley Reserve, amateurs blend their own wines, paying a membership deposit of $135,000 for the right to harvest, crush and bottle top grapes.

SHOWBOAT Launching this week, OpulentSea sells points that can be redeemed for yacht usage. Prices start at $27,500 for several days on a fully crewed luxury boat in the Bahamas.