Enough? no it's a start, I would adjust it higher but an LA of 11 is nowhere near what it needs to be or higher.
So let's do an LA of 13 just to say we did. Then give this guy a level in Wizard.
So we got a level 31 wizard vs. Elder Orb/Wiz 1.
Level 31 wizard has way more feats, more spells today, better saves, and perhaps more spells known. On the down side it has less hit points (62 avg for the wizard) than the beholder.
Now combat vs. one to the other is going to be a matter of who goes first at higher level. If the orb goes first it can't cast spells at the wizard if they are within 150' of each other as neither one can cast spells. Hand to hand combat is a toss up as the wizard COULD in theory hit but the beholder will prolly live longer to dish out more damage to the wizard.
Now spell slinging days are upon us! Beholder does not use his AMCone and we can cast spells aplenty!
1st round is upto whomever goes first.
Let's say Beholder goes first, let's assume 2 eyes disable 8 to use: Round one beholder blasts out 8 spells against the wizard (use the loadout from the descrip) casts darkness, uses disintegrate, wall of force around the wizard and then dispel magic on him. Let's say the disintegrate doesn't work, darkness does, and wall of force is up but wizard moves out, but manages to dispel half the wizards buffs.
Now the wizards turn: 1 Maximized cone of cold, 1 quickened cone of cold, it succeeds it's SR check against a paltry 30 (it needs to roll a 1 to succeed). So let's say it makes it's save vs cone of cold (although the DC is prolly in the obscene 30's) so that's 22d6=186/2=93 and then it fails the other cone 15d6=45 so we are at a total of 138 damage in one round alone.
Now I am probably gonna wager that there are better spells that I can pick to do this but i just picked these 2 off the top of my head and used them. This goes to show that toe to toe if a wizard 31 vs a supposed EL 30 beholder can whoop up on it very easily and perhaps kill it in 2 rounds. I personally would rather have the Level 31 wizard than the elder beholder so far.
Thoughts on this?