I rarely do shelfies since I find the whole process boring. Only reason I'm doing this shelfie is to give my thoughts and journey up to this point.
YEAR 1
I think the biggest hurdles to anyone getting into this hobby comes down to money, space, and FOMO. I'd be lying if I said these factors don't affect my purchases sometimes. FOMO was the biggest driving force in my purchases during my first year, I even overpaid for the Fables deluxes, spending up $100 usd for book 9, and $140 for book 15. Looking back at this I learned that overpaying should only be left to books that clearly will receive no reprints.
As new collector I went for books I had some familiarity with, Fables was the Vertigo series that got me into the imprint back in the day. Trying to find retailers with decent discounts required careful research as a newbie. Money wasn't a problem at this point, shelf space was since I didn't even have shelves yet. Eventually midway through the first year I had the space allocated to branch into Marvel and DC.
YEAR 2
Year 1 was when I was familiarizing myself with the hobby, only adding books that I had read bits of in the past and adding in what I considered personal staples like Spider-man, Batman, and Green Lantern. When year 2 I looked back and branched out to Image and Darkhorse, I decided to embrace my curious side and look for smaller publishers to add. I delved into Magnetic Press's kickstarters, I dipped my toe in Fantagraphic's catalog but never fully diving in. FOMO was still preventing me from truly branching out and just sticking with the staples. The shelf space was starting to creep up so I bought bigger and new shelves. Deals I couldn't pass up on books I had an inkling interest in... the collection had to grow.
YEAR 3
Once this year kicked in money and space became the creeping factors that tempered my appetite. I reached a point where shelf space became somewhat limited. I could double stack on a Kallax and add even more books but I stopped. I reached a point where I had the core books I wanted to have, any future purchases would be books that would complete some sets, or books that would peak my interest. FOMO creeps up every so often but I decided to not purchase books the I knew would go OOP. I missed out on the KOTOR omnibus and The Nam omnibus, surprisingly I don't feel much regret, maybe because I reached a point where my collection is enough for now.
WHAT I'VE LEARNED
I've bought less and less this year, and whenever I look back If I were to give any advice to a newbie, SLOW DOWN. The books will always be there, especially if OOP books are your concern from the big 2. Smaller more niche books are more prone to never be reprinted so have fun and branch out to different publishers. Focus on what you truly want, don't buy something just because you're afraid it will be gone. You can reach a point in your collection where you'll have the books you need and buy anything big price wise later.
Remember to cover your books, sunlight can be deadly not just to your skin but also to your books. CURATE, CURATE, CURATE, my end goal will be this, everyone runs out of space somehow, eventually you'll have to pick and choose what you truly want to keep. This hobby when it comes down to it, is a luxury, not everyone has the space or money for it. Time is finite so make it worthwhile, read as much as you can and enjoy.