Like many things from Unearthed Arcana, my initial and present reaction to 'level adjustment buyoff' was that it was horribly designed with little thought.
Non-goals of this question:
1. Whether LA races are 'fair' or 'balanced' in general and need a break.
2. The issue that it's worse for casters, generally.
3. High-optimization 'anything worse than the best possible build is fine' answers ("a full-caster-level- wizard/cleric/druid is better than anything else anyway..") - this is a question fr a more 'general' and not high-opt/Tier-1-uber-alles/Git/PvP setting
4. Justifying LA Buyoff by finding other things with similar problems (item crafting and Permanency/Wish XP has an issue similar to point 1. below - XP catchup by being lower level). I'm not trying to fix all of 3.5.
Goal of this question:
Do you have a better way to design a workaround for 'unfair' level adjustments that gets around the issues I cite below (or perhaps explanations of why they are not actually issues)?
1. Lower level characters get exponentially more XP for a given encounter (doubled for 2 levels down, 1/2 to 1/3 more for being one level down). So they catch up, and the racial features become 'free'. In a short term campaign, LA buyoff is worse than LA, in the long term, it's better - so it all depends on campaign length, rather than being consistent. If you have LA +2, you're behind by 1, then briefly behind by 2 at the moment you buyoff and everyone else levels, then you catch up. Surely this is bad design - various character development paths are ideally balanced across progression, yes?
2. Similarly, how it works if you start in a high level campaign seems weird or differently balanced. If you can start a high level campaign being only 3000 XP down for a LA +1, you'll catch that up much more quickly than if you had to slog through it going up from 1.What's the right way to do buyoff when starting at high levels? Do you start with the LA and pre any buyoff? Post-buyoff and 3000 XP short? Or post-buyoff and short by the amount of XP it would take if you did it at that level? (And can you buy off LA +1 at a level later than 3rd.)
3. It treats two LA +1 sources different than a LA +2 source potentially, and since the former treatment is better - 3rd and 6th rather than 6th and 9th - everyone who can will go for the former, using the drow racial class if possible, for example. Or does your second LA +1 have to be bought off at 9 rather than 6th?
4. The usual justification is 'level adjustment becomes eclipsed by class features and not worth it at high levels'. But everyone also says it's hardest to stomach at low levels, when it makes the largest proportional hit to your HP. A race with a Con bonus may have lower HP at low levels, but will eventually pass at high levels. Likewise Int and total skill points. So is LA most tolerable at midlevels? Sure, a fixed spell-like ability may become less useful, and things like spell resistance become more easily affordable from items (SR is priced at 10,000 gp per point above 12, and wealth by level is geometric). But why is +Str strength any more 'eclipsed' than your first point of BAB? Why is it sensible to be able to buy off a LA +1 template but not be able to buy off a 1 level dip of some class?