Get the best that you can without breaking your parents bank. But if you spend a lot of money make sure you include a Kryptonite lock so that it remains your bike. If you plan on doing 'serious' riding then go high-end. If it is going to be an all around banger, then think something else. No reason to trash an expensive high-end ride if you are not using it for its intended purpose. Steel frame will give you the best bang for the buck and be the most comfortable at a reasonable price. And are also the most indestructible of frames. But whatever you decide, ride and have fun!!