Because she's a newbie and it's all a learning curve mate.....a steep one at times too. And that's where the "old hands" (by that I mean experience over age) come in to show 'em the path.
And another part of the learning curve is figuring out who is providing useful information, and who is merely a rambling incoherent fool.
Kettles has good advice. Figure out a new price for something comparable and factor in what you want to pay used. And compare with the relative prices of other drum sets you see advertised. Does used gear go for 3/4 of the new price, or only 1/2? More or less?
Used gear is worth only what someone is willing to pay for it. There is no natural value to it, but rather, there is only the price that you (or someone else) is willing to pay.