Depends on the class. Torts? Crim? K's? are all fine with an old supplement. You'll be fine in Civ Pro with a post-Iqbal/Twombly supp (and actually, the easiest/best supp for civ pro would be Freer's barbri lecture). Con Law could be a little dicey depending on what your prof will want to emphasize.
I don't think there is a great supp for tax. Not much new in the world of evidence, so long as your supp covers the restyled rules. You shouldn't need a supp for PR. I didn't pay attention enough in BA to know if there's been recent changes in the law.
Thanks, I was thinking about getting an outline of contracts that was a version old/ 3 years cause its like way cheaper
99% of your contracts class is gonna be 18th/19th/early 20th century cases. Some UCC depending on the prof, but out of all classes, contracts supplements probably probably have the longest longevity. Probably be hard pressed to find an obsolete sup. Get the second to latest edition of farnsworth, say. same shit, less money. My mom's 25 year old farnsworth (contracts) hornbook served me well. shit's archaic as hell. other classes not so much