I'm a member, not a moderator, but I've read through the discussion here and this is what I think I'd do at your age and budget.
Up above is "Bidding.Helper". I'd click in there.
Then split my stay into two 3-night stays. For the first 7/21-7/24 it is mid-week so things are less expensive. Right now I can actually see a Hot.wire 4* on the strip at your budget. I'd grab it. Live it up.
Then I'd move on to the more expensive 7/24-7/27. Here I'd either pick the best Hot.wire deal within budget I could see, or the best PRICELINE EXPRESS I could see that was within budget (including that discount you have). I'd have to drop down in star level, and maybe do the "near strip" areas, but it still is Las Vegas and it would let me explore another area.
For that matter, you could actually just book the first three nights, then after you are there and better know the area you could book the other three. I might have done that more risky approach at your age.
To help you see the geography and your options better, it really would be worth your time to try that MAPS and HOTELS.com. There are links in several of your responses, or you can find it up in the Tool Box in the header. Enter Las Vegas and the desired dates, but change the "radius" to just one mile. Then zoom in on the map that appears. And use the little slider bar on the left to move down to a comfortable budget range and uncluttered things. The rates are higher than you will be able to do with Hot.wire and PRICELINE EXPRESS as they are direct purchase of a specific hotel (no taking a chance as to which one you'll get), but it is a great tool for an overview. Try your full range of dates, and then take a look at just the first three to see how the rates are much lower.
Romelle