The Countif function gives how many times a specific number appears in the range, regardless of its position.
That is why cells D6, D12, D14 and D16 appear in yellow. The number is repeated, but not at left, which I believe is the intention.
Change the number in D7 to 390000, and the property above is painted, giving a false positive.
If you wish to compare the listed versus the selling price in the same line, go the cell C2 and write the following formula in the conditional format box: =$C2=$D2. Then copy the format to the rest of the range.