Bartering items for other items and high-runes in game is perfectly acceptable currency. The main drawback is the majority of the player base doesn’t understand the actual value of runes. The average unlearned D2 player just thinks a high rune = high rune. “How many HR is that worth?”
When every high rune itself has its own distinct value based on demand. The highest being Ber, followed closely by Jah then > Sur > Lo > Ohm/Zod > Cham/Vex.
I would be fine with an abstract currency being implemented (such as how fg works) just so long as it disappears after ladder reset and can’t be bought with real money.