I've used Priceline very successfully for hotels, but never good luck for flights. I've bought 4-star hotels in NYC, Boston and DC for around $100 or less when the going rate is $239 or more. Just came back from NYC where I paid $96 for the NY Hilton when their website was quoting $279. Check some of the other discounteras ( cheaphotels.com hotles.com and see what the going rates are, then drop your bid by about at least 40%.
Hotwire seesms to work better, for me anyway, on flights - less so on hotels.