Hello. I am a new player of fantasy flight games having just recently bought the netrunner core. However a lot of my friends at my local game shop have switched over to Game of thrones second edition and i am considering picking up a core to join in. However because i currently dont have a steady source of income the chances of me buying more then one core is very unlikely so i wanted to know if i could get away with buying a single core and the campaign packs in order to join in at our local tournaments or would i not be able to build a decent deck like that?

You can make viable decks and play against others, enjoying the games and the community but, depending on your meta, I doubt you will win any tournament play. How many cores did the average player in your meta buy? Causal play nights may allow you to proxy cards. Don't let not having "all" the cards keep you from playing.

A single core is very limiting for deckbuilding, but as more and more packs come out, it'll be less so - as you'll have more options.

Still, at this early stage - with only 2 packs out, you'll still probably feel severely limited without a second core - especially if you're playing against opponents with 3. That said, in all the playgroups I've visited players are happy to lend cards (or decks) to help grow the local community, so my #1 recommendation is to stop by the game nights and check em out anyway!

With two cores and the first pack I have fewer than 50 of each faction card, which isn't enough for a solid monodeck. Most cards have only one copy in the core, with a couple of cards per faction having two, and there four each of the two popular roads. Each core has around 20 cards per faction. If you go as far as three cores you'll be able to keep four whole decks for different factions and include the roads. With 3-6 new cards for each faction per chapter pack it'll take a long time to get a decent card pool to build from, and cost more than simply getting a second (or even third) core.

If FFG can manage to keep it a game of widening options rather than suffering from power creep like some other games, those cores may actually be very competitive for a long time. Netrunner supposedly does that well - I've read about people who win tournaments just with core cards. AGoT 2e is a rebalance-reboot, so I have some hope they'll stick to a similar plan for it.

I would say that if you're going to spend $X on the game, your very best bang for your buck would in fact be a second core set. You're going to be hamstrung trying to build competitive decks with only one core.