Interesting - now if it had been a cruise voucher I would have said "yes, bogus" but sometimes a timeshare offer is real. The airfare is probably a scam.
But yeah, the main thing is their hope to sign you up for the travel club.
I have news for you, $1700 for a week in Hawaii is not that outrageously cheap.
This is a week at the Hyatt in Waikiki with air from JFK. $1500 per person: