Damage to Gold Ration: Wands

[Yogibear41]

Looking for the best wands (sorcerer/wizard list) that will give me the most bang for my buck, gold to damage ratio wise. Honestly more interested in eternal wands than normal wands.

Wands are for a cohort tool-box factotum that I plan to leave at the base 90% of the time, but want her to be able to do something damage wise if the base is attacked. So eternal wands would be great in a 1 encounter per day type scenario to add to the limited SLAs she already has. Less worried about action economy and more worried about gold efficiency, rather spend x gold to do y damage over several rounds than to spend >(x) gold to do Y damage in one round.

Figured Scorching Ray or magic missile is probably my best bet, but wanted to see if there were other suggestions.

[Vizzerdrix]

Can metamagiced spells be made into eternal wands? If so, then a cantrip with fell drain could be handy.

[Nifft]

Was the Factotum forced on you? Are you allowed to make a cohort replacement?

The best bang-for-buck is probably sending specifically to get PCs teleporting back to base.

For threats like a mob of peasants, something like kelgore's grave mist or malevolent miasma might solve the issue with no fatalities.

[Yogibear41]

Main reason I was leaning toward using factotum was because it knows every sorcerer wizard spell so if I need an obscure spell off the list for a weird scenario I have it. Without having to spend gold/resources to acquire it.

[Troacctid]

Amber amulet of vermin is very good bang for your buck. Since this is base defense, you should also consider magical traps and wondrous architecture, which are cheaper than normal items due to being stationary.

[RNightstalker]

Magic Missile will probably be the best bet, how many targets will have force immunity? It also doesn't require an attack roll and has a greater effective range.

[Troacctid]

If you're talking 1st and 2nd level spells, btw, I recommend a drow house insignia instead of a wand. Free CL upgrade.