Re: Nub question - items on cbn
I didn't list Ber to Jah because it didn't occur to me. I'll edit the original post and see if I forgot anything else.
I actually did Mal to Ist, Gul to Vex, and Sur to Ber many times last reset. I would even consider Um to Mal if you can't get a 3 to 1 exchange rate versus Ist (which gets much harder as the reset goes on), but you technically "lose" money when you do this. Definitely stockpile regular gems for cubing. It saves you a lot of hassle.
Only thing left for me unsolved is mergig low runes. I noticed on the last ladder (played only 2 last weeks..) that certain low runes (used for crafting) were often sold i packs of 20 and more for pul-ists. Ral, amn, tal, ort - anyting else worth keeping? I hate to see 10 mules full of el/elds and any other useless runes..
As a rule of thumb, if it can be used for a popular craft, it's worth keeping. You can check the Arreat Summit crafting page for more information, but these are the three big crafts:
Caster Amulet - Ral Rune
Blood Rings - Sol Rune
Hit Power Gloves - Ort Rune
There is lesser demand for these items but they're still popular: Blood Gloves, Blood Belts, Blood Amulets, Caster Belts, Caster Rings, Caster Boots, Safety Amulets and Safety Rings. Check the Arreat Summit for the corresponding runes.
Correspondingly, Perfect Amethysts and Rubies tend to be significantly more valuable than the other perfect gems. Perfect Sapphires to an extent as well. Unless you find a Safety crafter, particularly for amulets, Perfect Emeralds will
not have increased value in trades.
I don't feel you ever "make" money from cubing runes, but I've already listed the cubes where you "lose" money. It is, however, worth maintaining a single character stockpile of low runes (El to Lem) for convenience purposes. This character should be separate from your crafting and money mules.