Whoever buys runes from the shop is just wasting the money...

What determinates the category of "HR" is people's greediness. People mostly want as high runes as they can get and Ber rune is a very useful rune on its own (CB wep, DR armor) so it is considered the first HR here. I mostly accept Ohm+ because as I know in blizzlike servers Ohm+ only drops in Hell. At a server-wipe I traded many times with Pul+ considered as a HR because not as many people had runes to trade.