With the Topic Title saying much of what this post is about...

I feel the necessary question that I need to ask...

Do I need two Core sets to get a solid solitaire deck ?

Thanks in advance!

Depends what type of deck you want to build. I have built some decks now that don't even have cards from the core set in them at all.

But two core sets will make a big difference, since you will now have 3 copies of all but a few cards. I have three sets, and that does give me more flexibility to build decks with 3 fortune of fate and 3 Dwarven tomb for a Caldera deck. Of course it is quite easy to proxy a few of those cards.

I now think 3 sets is probably a bit excessive, with the current state of the card pool, but it does give you extra cards to keep some decks partially set up.

You will get a lot of mileage out of 2 sets, i'd recommend it, but I know many players are enjoying this game with just 1 set.

Playing with 2 or 3 sets is not cheating as some have suggested in the past, but you will notice a significant improvement in your decks. They will be more consistent, and you will have a better chance of getting the cads you want in your hand. The game will not become easy, but you will probably be more successful.

Although some very good players have used just the core set and nothing else to beat all scenarios in Shadow of Mirkwood cycle.

Tracker put it quite eloquently. A couple examples of decks that can take on the first cycle using one Core set are:

xanalor on BGG: http://boardgamegeek.com/thread/1108855/back-to-basics-a-killer-deck-using-only-cards-from

Dan (Beorn) on Hall of Beorn: http://hallofbeorn.wordpress.com/beorns-path/

I haven't tried out xanalor's deck, but the Beorn's path decks were effective when I tried them out during my first couple weeks of the game.

When FFG makes a Core Completion Set I'll buy it. Until that time I will shamelessly proxy since the rules say I can have three copies of each card in my deck.

One set and proxies is the way to go.

What does it mean to proxy, or to obtain proxies?

What does it mean to proxy, or to obtain proxies?

In my case, to use a card as another card.

Thank you all for much valuable replies!