I'm not an expert but it seems very high. 1) is it used? That would lower the price. 2) it's 10k. Usually jewelry in that price point is 14k or 18k. 3) diamonds under 1 carat are not as valuable as anything over a carat. Plus there are all grades of diamonds. It could be a cheap one with all kinds of inclusions. You could pay to have it appraised but I would take it to a jeweler in the mall and ask what they thought it is worth. It smells funny to me.