Hi Seerex, and welcome to the hobby.
Don't know if this helps, but here is my own personal experience. I started as a complete noob about five months ago. The GW store tried to sell me the MOM box but as it didn't come with paints or brushes and I didn't know whether I'd stick with the hobby or know anything about playing the game, I went with the starter set - this was 12 goblins + brush + 8 paints. I notice that the 'hobbit' version of this has just 5 models and costs more which is a bit pants.
Anyway, second month I invested in MOM starter set which gave loads more goblins and a troll plus the fellowship. Crucially I got the mini-rulebook too.
Month 3 I bought the 'citadel hobby starter set' that gave me another brush, more paints, some glue and some handy clippers (can't stress how useful these are). Plus I bought some loose paints and a spray can of primer.
Since then I've decided to expand my MOM set into my first two proper armies - a moria army and a dwarf army. So now I've got some heroes both armies, a couple of giant spiders, and an old box of 24 dwarfs off ebay. Also a couple of the LOTR sourcebooks.
In summary, my first few months were a compromise between investing in models and investing in paints/tools/brushes. My monthly spend has now stabilised at something more affordable and I can get on with painting up my backlog of minis.
Despite all the hype I've decided to leave the hobbit boxset until after christmas, when finances will be better. In the meantime I've got enough to be getting on with building my LOTR armies, plus a scenery project I'm working on, etc. In other words, although hobbit is the new best thing that everybody is (understandably) very excited about (and admittedly the rulebook will reflect the latest rule tweaks), if you were originally attracted by the wider Tolkien universe and the idea of modelling all sorts of scenarios including some that aren't in the films (eg last alliance, battle of bywater, Balin trying to retake moria, etc) and if you see any MOM sets going on ebay, then I would suggest still considering going down that route. I'm not sure yet how the models from the new Hobbit boxset will fit thematically with the rest, so if you're set on building a Gondor or Rohan army, then the new boxset may not be of much use.
If you want cutting edge rules and latest models plus lots of support from White Dwarf magazine and/or money isn't a deciding factor, then knock youself out with £447-worth of spanking new hobbit models to choose from. Don't forget that the latest rulebook might be redundant in a year's time anyway as GW will keep tweaking it, or at least will bring out extra sourcebooks/codexes.
My final advice would be to strike a balance between picking up stuff off ebay and small independent suppliers (eg our resident supplier at
http://www.greendragongames.co.uk), and going to speak with the staff in a GW store. It was a bit intimidating at first going into a store, and they will try to flog you all sorts of stuff you won't need right away, but I've found them also full of knowledge and advice and offer free painting sessions. Going there for all your supplies will seriously drain your wallet, but don't discount them totally. Afterall, the exorbitant prices for their physical product is what pays for them to run those high-street hobby centres, so why not pop in for advice or just some inspiration from the window display?
Well that's my advice as a fellow noob. I'm sure lots of others will disagree and they all have loads more experience than me.
Whatever path you choose I think you're going to have an awesome time so take the plunge and get stuck in.