Roy, there is a reason that the "Silwer Armor" she's selling is ONLY 1,000 gold...it's a cheap knock-off of the more reliable "Silver Armor"...
ADVICE: Build up your "Experience" a bit more and you'll be able to avoid shady sellers like her... remember that the labyrinths in Double Dungeons have been flooded with pirated items that have not been safety-certified.
ALSO: I noticed that the second elixir in your inventory has already EXPIRED (tell-tale brown bubbles collecting on bottom of the glass flask). Dude, double-check the expiration dates before you pay good gold for an elixir! Damn, how did you make it this far in the game with such shoddy items?