I can attest to the difficulty presented by the new tiers, mostly because it more or less passed me by. And honestly, I've never been happier to miss a cut in my life.
Your observation about current locks is most insightful. At my current level, I'd be MILES away from purchasing the clubs I have in my bag -- my driver/FW wood are locked until L57, my irons until L58, and my putter until L71! (What's up with that?). Only my wedges are 'close' at L49/50. Frankly, I'd be pretty hosed if I was in the Pro tier without such good stuff. That's why I waited until I made Pro, then immediately bought it. (BTW, I'd also be upset if I had to purchase it RIGHT NOW, before it gets locked up again on the 10th!!)
Add to that the fact that the levels aren't evenly spaced. From L20 to L21 took 415 EXP, from L25 to L26 is 750, and I understand that in the 30's, more than 1500 EXP is required to advance. In other words, what took me 2-1/2 rounds to achieve before will take me 10 rounds before too long. I cringe when I imagine what the level spacing will be like in the 70's and 80's. I think your 100+ round estimate is more than a little low.
I plan to hang around Pro for some time to come -- certainly until I have access to the clubs I want to have for Master. Since I was leaning toward i15s across the board, that means well into the 80's, level-wise. I certainly don't intend to compromise and just buy whatever becomes available at each tier, hoping for some incremental benefit.
I'd have preferred to make the move up when *I* thought I was ready, but this new system has made up my mind for me. For now, I'm keeping a really close eye on my average. No unlimited plays on KIA or STA, and lots of ranked rounds on BPB and especially OAK, which is challenging enough as is, without longer tees and inadequate tools.