The only thing you should be afraid of is if you think your plans will change. If that's a concern, I wouldn't use HOTWIRE or Priceline. Personally, I wouldn't use the sites to buy airfare. I've done far better keeping an eye out for a good sale, and the only time I bought airfare using these sites, I ended up with a horrible double connection flight. But I've had great luck using both for hotels, particularly with the benefit of this website. I've used Priceline in Las Vegas, Orlando and Boston, and ended up with a truly fabulous hotel each time, for a small fraction of the cost I would've paid elsewhere. Each time I was reasonably sure of which hotel I'd end up with, and twice I was exactly right (the third time, I knew it would be a resort around Disney, and we got the Gaylord in Orlando, which we loved). There is SOME risk, but booking a hotel is always something of a risk, even if you know where you're booking, since you won't find out until you get there if it truly is nice, or if the website has been spiffed up and the hotel is kind of junky--or whether you'll get a "bad" room in an otherwise "good" hotel. If you want to save some money, in my book, Priceline and Hotwire are the way to go. IMO, Priceline is a better deal, but slightly more risk than HOTWIRE. Good luck!