The common technique for time share developers to employ to persuade people to attend a time share presentation is to offer a gift of some sort. Up until now, there have been no legal taxes imposed on time share gifts and you should not believe anyone who tells you that you will have to pay such a tax at the airport before leaving a destination.
Time share gifts usually include complimentary meals, free excursions, discounts on accommodations, free bottles of alcohol, bicycles, and so on, all of which would be difficult to tax, even if there was such a law. A grey area comes with cash incentives, although most reputable time share companies offer money or vouchers that are redeemable against the purchase of a property rather than physical cash.
In most cases, if you are threatened with having to pay tax on your gifts at the airport, this is likely to be a scam to get you to return your free gifts. Avoid unpleasant time share experiences and chose a reputable company with a good track record.