I beleive Skillers are lvl 42. These can drop by lvl from a few things in Norm, and almost anywhere in NM as well. NM cows isnt a bad place to hunt these.
Trying to roll specifically for skills IMO isnt a good strategy. I have a friend that wants to do this and i think he is nuts. Sure its possible, but I would rather try and collect those lvl 90+ charms like from Act 5 Super Uniques and Baal and roll for the big stuff and hope the lessor rolls might get me some skills.
There is no way to know "legitly" what lvl a charm is unless a specific monster drops it and you know it and you go look up his lvl and this could be a pain but power to you.
If you specifically want Skills and nothing else then you want the lowest possible charm to get skills as it then cannot spawn the higher lvl mods thus narrowing you possible mods that can spawn. Problem here is that you eliminate the possibilities for the really good ones that might trade for 2-3 skillers
Once when i was making a mule game, my barb did Baal just to pass the time and he dropped a skiller, so baal in normal can drop skillcharms. Am i wrong in assuming that normal Baal grand charms can be rerolled in to skillcharms?
I beleive Baal is around lvl 50 in Norm, and many monsters in NM Act 1 arent his lvl. It would be best to look that up to be positive.
Taking charms you have laying around and rolling them unless you specifically know where they came from could be a simple waste of gems. I suggest taking your next dropped grand that you know where it came from and start there.
If a monster drops you a skill charm then that means any charm he drops could be cubbed as a skiller.
I will take Chiller Babes advice and keep my charms from nightmare act 3 on. I have higher than that so I will use those first and work my way down as I run out. Just wanted to purge the ones without potential.
Thanks again for the advice everybody, I appreciate it.
When I am thinking about it I typically just save any bad charm I find in hell to later cube. Putting aside any from hell baal as particularly tasty . For other areas just save bad charms that are of a lvl equal or greater than something I would like from a cubing. (saved a few +1 max small fines since I know they could potentially become nicer fines with cubing for instance. but unless I mule the charms to my cube mule I will typically toss bad charms I find on random mules if I can no longer remember where it came from. (at least if I am looking at mules from the early days of 1.1 later mules I know that bad charms are cubers )