Hi,
Well, if you want to change the prices of variants, you'll need one row for each variant too in your CSV, and you'll need also one column for each characteristic to specify the value for each variant and the main product's default values.
However, since all your variants have the same price, why have the price in the variants and not only in the main product ?
I would rather recommend you leave your CSV like this and just remove the prices of the variants. That will be easier to manage in the future.