Hey! There are a couple of different things that you can do. It all depends on how many people there will be and what all you are looking for. There is the Chapel in the Clouds at the Stratosphere which is cool if getting married at the top of the needle is what they want. You'll have to check their site for exact amounts. There are plenty of other options at most of the hotels. There is always a basic one and then you can add-on things. Just check for photography, As for the Valley of Fire, I think, is going to be more than $750, but I'd check the forum on that to be more certain.
If you could give a few more specifics, like how many people and what type of setting you are looking for as there are so many different places (lakes, boats, parks, restaurants, hotels, hotel suites, desert). Also, you might want to check the forum for some ideas as well.