Hi,
I just started playing and after having watched the excellent "watch it played" videos, enjoyed my first couple of games.
I can see I am going to love it and I want to expand, but I've joined late, I notice many sets are currently out of print, where should I start? Should I get the deluxe additions first or go straight to the adventure packs?
Thanks in advance.
JJ
Hi Jim,
Glad you are enjoying the game. 
I would recommend getting one cycle at a time. While buying the Saga expansions whenever you want.
Having played all the quests and used the players cards in each of the packs, this is how I would buy if I were to recollect LOTR LCG:
1. One Core set
2. The full Mirkwood cycle (all six adventure packs)
3. Khazad Dum deluxe expansion.
The above will keep you busy for a while. Considering you already have the core set, you can pick up the above for just under $100 at Coolstuff Inc. Here is the link https://www.coolstuffinc.com/ They have everything released for Lotr lcg in stock except for the Stewards fear AP. After that I would continue like this:
4. Full Dwarrowdelf Cycle (all six adventure packs)
5. Saga Expansions (The Hobbit: over Hill and Under Hill, The Hobbit: On the Doorstep, Black Riders)
6. The Massing at Osgiliath, The Battle of Lake Town, The Stone of Erech
7. Heirs of Numenor Deluxe Expansion
8. The Full Against the Shadow Cycle
9. The Voice of Isengard
10. The Ring Maker cycle
11. Nightmare Decks
I'm sure this is overwhelming to you but it will make sense later. In other words, start out with the full Mirkwood cycle followed by the Dwarrowdelf cycle. You don't have to buy all six adventure packs at once, but I would recommend buying them in order.
Most people here will also agree that the Mirkwood cycle first, is the way to go. Followed by Khazad Dum the Dwarrowdelf cycle. If you don't have the money to buy tons of expansions and only want to get just a few, take a look at this - http://talesfromthecards.wordpress.com/2013/09/13/new-player-buying-guide/
When I was right in your place I thought to myself that I would only buy a few expansion and not collect everything......a couple years later and.......I bought everything. 
I'm warning you, these LCG's are very addictive and you might end up spending a lot more than you would have thought. I have this one and Star Wars LCG and thats too much already... 
Feel free to ask questions,
Khamul
Welcome to the game!! I'm glad you're enjoying it and planning on getting more! Everything above sounds perfect, try to go in order as that is the easiest for many reasons and the best plan. Also check out Amazon and Ebay they should have all the packs and at a good price (12-13 bucks for the small Adventure Packs).