This doesn't seem like a good buy for a new toon since at level 1 it lasts barely over a minute and has a 1-pt ds.
But it does improve with level. For example at level 13, it lasts 3 minutes and does 7 points of damage.
Plus it stacks with druid damage shields.
Problem is for young players, the price for this factors in demand from rich high-level players.
I can dig why the damage would be so low at the low levels but the duration should be longer. A 1-pt DS potion which barely lasts a minute is rather useless at any level, really, especially considering the funds available to a true noob.