To cube runes, or not to cube runes, that is the question!

I've recently found 2x Sur, 1x Ber and 2x Jah in my travels in, around and through Act I-V. I want to make an Infinity for my Nova sorc, but I'm not sure what the best way to make that happen, is. Should I cube the 2x Sur (mostly worthless anyways, right?), or trade the Jah for lower runes, most likely 2x Ber? What is the prevailing strategy here, I want to do what makes the most sense for these valuable runes!

Assuming ladder you can just cube them. Jah i'm not sure you can trade down to 2x Ber

If you're on ladder and have some patience, you can sell the Sur for Lo+ Vex, or possibly Lo+ Ohm, then buy a Ber for Sur+ Lo. In then end you'll have Ber+ instead of just a Ber. Finding someone willing to sell the Ber for Sur+ Lo might take some time though, might have to add something more. Cubing would be faster, obviously, and the net gains from going the trade route vs cubing is not really that big. If you're fine with losing a little bit of value from cubing then go ahead.

FWIW, the only mid/high runes I'd consider cubing on ladder are Gul to Vex (only because Mosaic isn't available anymore) and Sur to Ber, but unless I'm in a hurry I'd rather try to make trades first instead. I actually did cube 2x Sur to a Ber once back in season 10 - I had a Sur, a Lo, and a Vex, and I was trying to buy a Ber with that, but noone would accept my offer - so instead I bought a second Sur with the Lo+ Vex and cubed the Surs to a Ber.

Also, Jah is not worth 2x Ber on ladder. Anyone reporting such a sale is either trying to manipulate the market (in order to trick others into believing that's what the exchange rate is), or was taking advantage of someone less informed (akin to scamming). The actual exchange rate between Ber and Jah varies over a ladder season, currently seems to be Jah = Ber + Ohm/ Lo.