You may want to check with the Courtyard @ Downtown Disney. When we were there our last trip, there was a fellow in the lobby that signed you up to visit the Marriott timeshare property. At that time the reward was $100 marriott certificate. We had other people with us and I was not able to do it - he even told me I could go without my husband (HE NEVER TRAVELS WITH US!-hates to vacation). We needed it too because we were headed to the Renaissance at St Augustine after we left there!
If I get a free afternoon, I fully intend to go back over there and see if the offer is still as good. I also believe Florida law limits the time-share sell time to the 2 hours so if it had reached that- you can cut them off and force them to stop and give you your incentive.
One of my friends did a tour and actually bought-they received a full cruise for buying which she said was wondeful-before they left on the cruise they went and toured the sister property at the place the cruise departs from and received upgraded rooms, etc and a bunch of other bonuses. I assume the gifts were nicer because they purchased.