it gives only +5levels, and it working if u planing to wear r99 gear on 85 char then its useless.. on 90 u can r95, on 94lvl u can wear r99
Rune of crystal does only help with 5 lvls basically, as it was mentioned before. If you plan to wear R99 gear on lvl1 toon without penalty it's easier and probably cheaper. You go fishing, or fish the AH for whale blubber (prices are from 2kk to mad) and buy expertise runes @fishing guild guys in each town. The price of R99 rune is like 20 pieces afair. You open it, it works 2h, then you need another one. End of story.
@Zousem Hello! Could you please explain in details what did you expect from the Rune of Crystal? It is working as intended - exactly as explained above (thx @Sanek and @cmec1). If you mean another rune not working, please let us know.