What type of calculator should i get?

I am doing an associate's degree in maths, and I am looking to purchase a graphing calculator to help with my studies and beyond. I am presently doing Pre-calculus, with intentions to move onto Calculus in my future studies. I have been trying to source an economical yet ideal texas instrument, that will be good enough for my use in pre-calculus, but will also be comprehensive for calculus and other topics in the future. Is there a big difference between the TI 83 plus, TI 84 plus silver edition, TI 89 Titanium, or the TI Nspire models??

Check the comparisons in the link below...

which should i get? Should i work with the cost factor as well? or should i ignore the cost as a factor and invest in quality and features? Would a more advanced one be too advanced for use now? I am not looking to purchase another calculator after this one in a hurry.

Which Calculator Is Right for Me? by Texas Instruments -US and Canada