so i notice alot of the expansions are out of print. my next question is this- can you play an expansion pack in a story arc out of order?

Yes. But to play any of the dwarrowdelf cycle you need to have Khazad-Dum expansion(because the Adventure Packs in the Dwarrowdelf cycle need some cards from the Khazad-Dum expansion.) So you can buy any of the Mirkwood cycle. And you can buy any of the Dwarrowdelf cycle if you have KD.

And there is also the hobbit expansions and heirs of numanor expansion.