Priceline bonuses aren't mentioned much, they are one of the hidden gems you have to dig for.
Let's say you have a $10/day bonus for up to 5 days, with a 3 day minimum. You bid $20/day for 5 days on a 3 star. Priceline adds the bonus and makes your bid $30/day. Let's say instead that you want to stay for 10 days. You bid $20/day again. Priceline divides the max bonus by the number of days and makes the bid $25/day. Something to consider:
Le's say you wanted to spend 3 days close to Universal and 3 days close to WDW. You have your $50 bonus, $10/day for 5 days. You bid $20/day on the Universal hotel. Priceline adds in the bonus and makes it $30. You win

Now you go to bid on your other 3 days. You bid $20. Priceline adds nothing. You have one chance to use your bonus so pay attention to the details and maximize what they give you.
If you go to sites like betterbidding and biddingfortravel you can usually get an idea of what hotels are awarding winning bids. You can also get a list of hotels in your star range and research them. Between these 2 strategies you can get a decent idea of where you will end up. If you also are on a budget, especially one trying to get off as cheaply as possible, go in with the attitude that you are looking for a comfortable, safe to sleep and you can be pleasantly surprised when you get something that exceeds your expectations. I've been using Priceline as long as there's been a Priceline and I can say that I've never had a room that would have made me regret bidding on it. Something like a resort fee is an annoyance but it still only made the room $33/day.
Here is a little tip you can use as an insurance policy if you are the skittish type. I've never had this not work though theoretically it's possible at a super busy time. Let's say you wanted to stay in Orlando for a week but you're nervous about being stuck in a dump for that amount of time. Bid for 2 or 3 days. When you win, Priceline will tell you the name of the hotel and offer to extend your stay at the same rate.
Now you have a name, a location and a rate. Open another window in your browser and check out the hotel. Read the reviews. Call the front desk and ask if they have a resort fee or charge for parking. Satisfy yourself that it's where you won't mind staying. If it isn't you only have it for 2 days and can look for something else. If you like it then extend your stay at the same rate. It will actually cost you a couple of dollars more because they will charge you a 2nd booking fee but it's worth it for the peace of mind.