I think you can use window films. There are so many types of window films, which are used for restricting the sunlight to come into your room. Use the best quality film and it will be in your budget too.

I have a set of the classic vertical white blinds that turn and can be pushed to one side, just the cliche white blinds. Well I am not allowed to remove them because its against the rules in the apartment complex I live in. The blinds just don't stop much light at all and they make a lot of ouse when I have my fan on so I want to mount a shade just above the indent for the window on the top. Is that possible? I don't want to use a drape, so would I be able to install a Cell type blind at the top or what are my other options besides drapes. I am on a low budget so the price should be less than $100, and the window is 70"W x 48"H and I would like an inch on either side so actual measurements will be 72"W x 50"H. I was thinking something like: http://blinds.homedepot.com/control/product/productID,97659