Although a level 2 character with an ECL of 4 is supposed to be stronger than a level 2 character, they do not match up to a level 4 character by any stretch of the imagination. But let's pretend for a moment, that they do.
Even on the SRD, they point out the fact that level adjustments are more of a burden then they're worth, especially at higher levels.
From the SRD:
http://www.d20srd.org/srd/variant/races/reducingLevelAdjustments.htmWhen a character with a level adjustment advances in experience,
the level adjustment he started with becomes more and more of a burden.Eventually, the benefits of the creature type may come to be eclipsed by those of his class features, and the player may regret his choice of race. Under this variant system, the character can pay an XP cost at certain intervals to decrease the burden of his level adjustment.
Once the total of a character's class levels (not including any Hit Dice from his creature type or his level adjustment) reaches three times his level adjustment, his level adjustment is eligible to be decreased by 1.
Now I know that programming in LA Buyoff is likely difficult if not impossible. But let's see what "XP Value" is placed on these level adjustments:
The character must reach a level equal to 3x his current Level Adjustment
Starting
Level
Adjustment Number of Class Levels Necessary
for Level Adjustment Reduction
(Not Including Racial Hit Dice)
1 3
2 6,9
3 9, 15, 18
4 12
5 15
6 18
After reaching the listed levels, the character can pay XP to reduce his Level adjustment. The character must pay an amount of XP equal to (his current ECL -1) × 1,000
So according to this:
LA+1 is worth 3000 xp (Because it can be bought off at level 3, ECL 4)
LA +2 is worth 16000xp (requiring buyoffs at level 6 (ECL8) and level 9 (ECL 10)
LA +3 is worth 45000xp (Requiring buyoffs at level 9 (ECL 12), Level 15 (ECL 17) and Level 18 (ECL 19)
The XP Penalty idea is a good one. It's much more severe than the normal Level Adjustment buyoff rules, but accomplishes much the same goal.
LA +1 at a 10% penalty is worth 19,000 xp By level 20
LA +2 at a 20% penalty is worth 38,000 xp By Level 20
LA +3 at a 30% penalty is worth 57,000 xp By Level 20
These are not small XP amounts. Any player who pushes through these penalties and reaches higher levels should be rewarded, because their playthrough was more difficult. Good game design should reward completing difficult tasks. Even if we increased the penalties, I'm sure players would be more than happy to pay them.
TL;DR, I support implementing an XP penalty system instead of a level adjustment system, because Level adjustment in 3e and 3.5 is hamfisted and broken (and not in the good way).