Hint if you ever attend one: turn to your partner after the introduction and say "I don't know honey, we would have to sell the RV". They know that people with a RV rarely buy so they are much more willing to stop wasting their time.
The other option is go on vacation, send your parents to the presentation, and you take the freebies. This worked for a friend of mine- his parents old/disabled enough that they couldn't enjoy scuba diving and the like anyway, they were mentally competent enough to not sign anything, and they enjoyed the presentation better than the other tourist traps in the area.
I'm not sure how anyone can enjoy the presentation. Our presentation quickly devolved into insinuation, badgering, bullying, intimidation and finally: outright insults.
It doesn't make economic sense, but once they find out your not going to buy it, they spend the rest of the time making you'r experience as horrible and stressful as possible. Perhaps to dissuade others from doing what you just mentioned.
The other option is go on vacation, send your parents to the presentation, and you take the freebies. This worked for a friend of mine- his parents old/disabled enough that they couldn't enjoy scuba diving and the like anyway, they were mentally competent enough to not sign anything, and they enjoyed the presentation better than the other tourist traps in the area.