New to Marvel how to start

Hi guys, I played Arkham recently on family gathering and I had a blast but tbh the depth and complexity of the game kinda threw me off I much more enjoy simpler more casual games and friend told me he had Marvel champions and it was amazing game for him. So I wanna start playing and have tough time to decide what to buy. Honestly there is plenty of options out there with used games with much better pricing than buying all the stuff new. So is there some excel or a list of every expansions I just want to sort it out somehow and get sth within my budget that would bring me most fun. It's just feels more reasonable to save some money and get used sets instead of new. Any recommendations of absolutely fun expansion's hero packs that are good to buy in the beginning of my journey with MC