Jackie always behaved with a great deal of dignity -- something we *never* see anymore.
As for Ari, my understanding is that he had the manners of a pig and a mouth like a sailor -- must have picked it up around the docks

Of course she married him for the money -- that was never a secret, not even to Ari. He wanted the prestige she would bring to the union. She loved clothes and an elegant lifestyle for herself and her children. Despite what anyone tries to convince him/herself, it takes a good deal of money to dress well -- the quirky, vintage store look wouldn't have worked for her.
Why she's noteworthy ( to partially answer someone's earlier post about why she was famous)...
Jackie practically won John's second Presidential term. She vigorously campaigned for his reelection ( and I believe she was having a difficult pregnancy during this time, someone else can check whether this part is correct) because John's campaign managers knew Jackie's worth. She really pulled in the votes.
She was a national treasure with foreign relations/policy. Fluent in at least French and possibly other languages as well, she was a great communicator.
Most importantly ( and she would have agreed with this), she was a FANTASTIC mother. Her kids came first ALWAYS.