I'm currently taking a high-school pre-calculus class and next year I'm going to be taking AP Calculus and Physics I. I plan to major in Physics in college and I'm looking for a calculator that will get me through all of that. I need one that's approved for the SAT, ACT, AP, and is powerful enough for advanced Physics classes. Can anyone recommend a good one? I've only really seen TI calculators but I know there are other good ones out there. I'd also like to stay within a budget of $60 (used on Amazon). Just for reference, the TI-83 Plus Silver Edition is $60 used on Amazon and new ones are $165. I know I can get them from other sources but I'm just trying to get a common point of reference.