Air mattress for long term use?

I am redecorating my bedroom and really love the look of a full sized or queen sized bed, versus a twin (which I currently have). I am a senior in high school and am moving out next fall I suppose :) so it won't be for too long that I would use it. Like, less than a year. I was thinking I could get one of the $30ish air mattresses from Target. My parents wont pay for a new mattress at all. The subject was very quickly shut down. So, is this logical? Thanks!!! :) I am going into college, so definitely will be in a dorm. Which has beds/mattresses for you.