chrisann said:
We need a night for our trip in October, when is a good time to do priceline?
The first thing I would recommend is making a reservation that you can cancel. I use orbitz to search for a good rate and hotel, but make my reservations directly with the hotel through the hotel website so that I can cancel it usually before 6 pm the day of travel (each hotel's cancellation policies will vary).
Next, as others have suggested, monitor the biddingfortravel or betterbidding websites to see what other people have successfully bid for a hotel. If you see a rate and quality that you like, go ahead and bid it following the bidding strategies that are thoroughly explained on the website.
What you'll notice is a trend. For example, $36 - $38 seems to be the going Priceline rate for a 2.5* near WDW. So, if your interested in the 2.5* hotel and you're happy with the $36 rate, seeing that your trip isn't until October, I'd try to make a Priceline bid at $36 for your date and see if its accepted. If its not, you can try again every 24 hours and get more aggressive with your bidding as you get closer to your October trip.
Is it better to bid closer to your date? I'm sure that supply and demand does play a factor in the likelihood of your bid being accepted. As you get closer to your departure date, if there's a lot of supply, the participating Priceline hotels will probably be more willing to accept your bid.
One last thing to remember is that you are pre-paying for the hotel and it's non-refundable. I don't think I'd risk pre-paying for a 7 night stay 5 months in advance since it's a lot of money to be forfeited if some unforseen event would occur to cancel your travel plans.