Hmmm, surely this has been mentioned before:
Yes it's been mentioned before.
And so has the next
few paragraphs. Because the section you quoted from only applies to LA's of +1.
If the level adjustment is greater than +1, this process repeats until the creature’s level adjustment reaches +0. Each time, use the creature’s current level adjustment to determine the point at which the level adjustment can go down by 1. For example, a drow (level adjustment +2) may drop to level adjustment +1 after gaining her sixth class level, and then to +0 after gaining an additional three class levels.
Now at this point I'm sure you want to try one of two things.
A. I think repeat means start at 0 and redo 0 NI times!
B. In the single LA entry it uses the word total, that totally applies right?!
And both are them are pretty dumb. You have six examples and a table quantifying the meaning of repeat and you don't get a browny button, or a pass, to ignore them.
Table 1–1: Reducing Level Adjustments gives the levels at which level adjustments are eligible to be reduced for starting level adjustments of +1 to +6.
And the text entry outside of examples does in fact make a clear distinction of simply "LA" vs starting LA.
And bonus point. I have no idea where you're going with that emphasis on immediately there seeing how it's in total opposite in regard for your intended goal. You have the choice of paying it or not "immediately upon becoming eligible" and eligibility is checked when you reach, ie level up to, the desired value. So if you were ever higher than the desired value, either by refusing to pay now or really sucked at reading, there isn't actually any text supporting the interpretation that you can buy your LA off if your total has already passed up the moment you were at the desired value. It makes sense to allow buy off later on, but if you came in RAWhumburg this or RAWhumbug that, it's the exact thing you wouldn't want to bring up.
Purposely bad reading are as always, purposely bad readings. If you wanted to subvert LA, consider things like True Mind Switch, Fusion, Ability Rip, Manipulate Form, Assume Supernatural Ability, Factotum 15, etc. I mean, there are ways to actually do it without having to pick up a funny smell just to achieve something Spellcasters can already do for free.