>>121300155Claremont's run started at like issue 94. the prior stuff established important things (mutants, Xavier's school, Magneto and pals, Sentinels, Juggernaut, Savage Land etc) but the basic shit was covered by the movies more or less and like 80% of the X-men's most memorable stories and characters happened under Claremont's run. hell pretty much all of 90s cartoon was adapting Claremont's stories.
start at Giant Size X-men #1 for the introduction to the new status quo then Uncanny X-men #94 then read till you get sick of it.
Marvel stopped doing the essential collections (black and white on shitty paper but a lot cheaper) so its Omnibus, masterworks tpb or the epic collections (those releases jump around a lot in the story tho).volume 1 omnibus isn't hard to find and goes for like $58-61 bucks and has like 39 issues in it.