Just because you didn't need a laptop in highschool doesn't mean the OP doesn't. Either because his HS requires one, his parents don't want to share their computer, or whatever his reason is is kinda irrelevant IMO. If (s)he wants a laptop, and his/her parents are down to buy him one, it's not really my place to judge his reasons.
I say get a new base 13" pro and 3 years of AppleCare. I don't get why anyone would say to get a $500 POS clunker to use for 4 years; if your family is in the position to get you a Mac, why not? You shouldn't has to suffer with a junk laptop through highschool if you don't have to; and to everyone who's thinking something along the lines of "it's crazy to spend $1xxx on a laptop for a kid," to some (more like a ton of, but won't get into semantics) people it's not like that is a lot of money to spend, let alone on something that will last a few years.
To recap; no reason not to get a good laptop, I say 13" pro and 3 years of AppleCare. Enjoy