Should I buy an Iphone or keep my prepaid phone?

So I'm a college student and currently brought my cheap cellphone from home. I have never had a cellphone with a contract and the only one I have at this moment is the 20 dollar one that my father bought me years ago. I'm able to purchase a phone now because I can pay it off with the financial aid but I'm having second thoughts about it. I can buy those cards to add minutes and I would be spending 20 dollars for 120 minutes. This phone has access to texting but obviously isn't touch screen and is less trendy. If I were to buy a cellphone, I would be paying $70 a month which means I would be paying over $350 per semester in college. I could be using that money for something else, especially in college but not having a cell phone has done some damage, I have to admit. I can't socialize as much because I know they will ask for my number and I have to say "I don't have one." I mean what 18 year old college student doesn't have a cell phone? It gets to me sometimes. Like I said I could be using that money for something else, especially in college. Should I just keep my cheap, old prepaid phone and save up to $350 a semester, or should I buy an Iphone? Any input will be highly appreciated.

Depends on your budget if you are leaning towards buying an iphone
then maybe sell your prepaid phone to get a little bit of money and just save up your money and I know that's really hard to do but whatever works for you is better.