Yeah, I really am confused at what I should do. I think that's normal though, for someone who has been on-and-off this game for nearly 13 years and *finally* goes in head over heels...and loves every second, every nuance of it.
In regards of buying a whole set, I think what I dislike most about this idea, is the fact that I'd buy (and pay) for a lot of stuff I don't need, while not really getting what I *really* need (aka lots of fixed, commons - and even uncommon cards, seeing how I don't have enough of those non-uniques.).
That's why I thought of a Starter-display. I'd get lots of commons and uncommons, some rares (obviously 6 less than with boosters, right?) and fixed cards. If I am lucky, I'll get at least one set each, if not... tough luck. I don't think the chances are that bad. Then, if I still needed to, at one point, I can always buy a "complete" set to finish of the collection, maybe trade off a few cards, or just keep them.
And yes, I hope that I will be able to attend some meeting/event, but first I need to play MORE!
Oh and I guess I can quickly post a list of cards that I am missing completely, just so people can judge better (as you said - some cards aren't that useful, so one would only get them for "completeness"):
METW Fixed
Aragorn II Barrow-downs Beorn's House
Bree Ellahan Dunlendings
Dunnish Clan-hold Faramir Gandalf
Gimli Glorfindel II Goblin-Gate
Henneth Annun Iron Hill Dwarf-hold Isengard
Kili Men of Anorien Peath
Rangers of Ithilien Rangers of the North Ruined Signal Tower
Saruman The Lonely Mountain Thranduil's Halls
Weather top Wellinghall
METW Uncommon
Balin Eomer Fili
Magic Ring of Courage
METW Rare
Arwen Anduril Army of the Dead
Adunaphel Agburanar Akhorahil
Balrog of Moria Bane of the Ithil-stone Barad-dur
Clouds Cirdan Cirith Ungol
Clear Skies Elrond Elf-Song
Eye of Sauron Fair Travels in Dark-Domains
Favour of the Valar Fell Beast Galadriel
Galva Gollum's Fate Great Ship
Gwaihir Haldalam Hiding
Hobbits Isles of the Dead that Live Khamul the Easterling
Leucaruth Lucky Search
Magic Ring of Courage Minas Morgul Morannon
Mouth of Sauron Palantir of Osgiliath Sacrifice of Form
Secret Entrance Shadowfax Shelob's Lair
Smaug Southron Oasis Storms of Osse
Thorin II The Precious The Will of Sauron
The Stones Thief Tolfalas
True Fana Uvatha the Horseman Variags of Khand
Vale of Erech Vygavril
METD Rare
The Riddle Game Nenselde the Wingild Scatha
Were-Worm Agburanar at Home
No Escape from my Magic Subtlety of Guile
Promotional cards I'd need:
Black Arrow x2
Fatty Bolger
I am currently in the process of compiling better lists, especially in regards of checking what I need exactly for the five decks, or maybe even what I'd need in regards to have three of each non-unique. I have, as said, a nice amount of cards and I am sure I already have three of a couple non-unique rares, but I'll have to check to make sure.

I finally need a good overview of my collection.
In regards to Balrog cards... is there anything else but the two (bigger-than-starter-deck)boxes? Because if not, I bought those maybe 6 years ago for 10€ each.

Yes, I know, people will now pelt me with rotten fruit and rocks. I had no idea they were that expensive and I gobbled them up, together with a whopping 3 boosters of AS (for 25c each) at a local game-store, who had them in the bargain bin. I also got two boosters of Battletech CCG, 10 of Perry Rhodan CCG, one of Shadowrun CCG and ~25 of Mythos CCG.

It was a fun day of spending little money for many little things and I am very happy about that.
Anyways, I am concentrating on METW for now. Maybe METD, because I don't think I need a lot in there (in regards to getting three of each non-unique - seeing how I am missing only 7 rares). I'll also try to get my hands on all the TW and TD books.
I guess Dark Minions will be next, then Lidless Eye and then Against The Shadow. I already have some 300+ of LE and a whopping three boosters worth (36) cards of AS.

But that's in the future. Hopefully the near future, but definitely not on my list right now. Unless someone makes me a superb offer, or I stumble over something. The only thing I will actively look for, is the books, as they seem quite rare.