Question: I want my character to have extra arms.
Now, the easiest way to do that is Aberrant Limbs from DMG2 pg. 158.
There are two problems:
1) These abilities were primarily designed for NPCs. They're allowable by DM's approval, so I'm asking for that.
2) These abilities come with level adjustments. Now, since they were primarily designed for NPCs, the CR adjustment is relatively accurate but the level adjustment is not (which is something they admit). Aberrant Limbs is a +2 level adjustment and quite frankly I think that's too high. To wit: Drow, also a +2 LA, gets spell resistance, increase ability scores, some minor spell-like abilities, free weapon proficiency, and a weakness that is easily overcome by darkened goggles (which have since been printed). Aberrant Limbs give you two extra arms and multiweapon fighting. I would argue that Aberrant Limbs is only a +1 LA.
Now, regardless, I'll probably use LA buying off rules from Unearthed Arcana to buy off the LA with XP, which means that I'm probably going to end 6th or maybe 5th level (spending XP for items as well).
Also: my character concept has a background in a culture that is very high on the use of magic (hence multiple limbs: magic mutation). Before I go creating such a culture in your game world, does such a culture already exist and can you give me some info about it?