Raising initiation grade is relatively easy indeed, and probably the first thing you should invest in as a mage (you can probably do the first one after your first run). And while Centering isn't too useful as your first, getting it at 2 or 3 certainly adds a lot. Add a focus and it's not hard to hit 18 drain dice fairly early in your carreer, which helps a lot.
Define easy. If you mean you can raise it at the expense of ever increasing your Skills or Attributes or Binding Foci, then sure, I guess its easy.
And how are you getting it after 1 run? Maybe if you've already planned out your Arcana skill & then saved 7 Karma at Chargen & then also get 6+ Karma for your 1st run. That takes some pretty dedicated set up if you ask me.
Investing 30+ Karma to get +2 Dice dice for Drain & Counterspelling is a bit much IMHO.
And all it really promotes is to put off those "by grade" powers till later which then promotes Quickening first.
We all say that Quickening is overpowered and I don't disagree but when the other options have also been gimped badly then it just promotes making the non-gimp choice.
Making that go from 2 dice to 4 dice for the 30 Karma actually makes that choice somewhat debatable.
Or as someone else said, remove Grade from the equation & use a different stat, like adding Magic to Drain dice. That gives you a bigger boost at the start & will also push you to upgrade your base Magic stat as well.
Getting initiation grades is a tradeoff, yes, but there's a reason people tend to do it -
it's worth it. And it's not like it cuts you off from other methods of advancement, it just happens to be one that gives a lot of bang for your buck (so do foci though).
31 karma - that's including a rank of Arcana, otherwise I don't see how you're getting 30+ - gives you +2 to drain and counterspell, yes (if you go that route). Is that worth it? Getting counterspell up 2 ranks will cost you 30 karma by itself otherwise. Granted, Shielding doesn't give you bonus dice on dispelling active spells, but counterspelling pool is the main benefit anyway. Drain Pool is a very important stat, and any other way you might have to raise it up will set you back much, much more then 30 karma (granted, also giving secondary benefits). The 31 karma for 2 initiations gives
both, plus the general benefits of initiation.
And that's if you stop at 2. Initiation is the gift that keeps on giving - if you initiate a third time, you not only get an entirely new metamagic, but also a free +1 on your drain pool and counterspelling pool. It also opens up Metamagic Foci.
It's expensive, but everything that's worth it is. And centering has it's own drawbacks (it takes a free action for one - so you can't declare counterspelling at the same time). Arguably, getting Shielding of Centering first is not an optimal choice and you're better off with a flat one first. But that's not because it's not a powerful choice by itself - it's because the flat-rate ones (or the ones with a high baseline, like Masking) are arguably too powerful at grade 1.