OK, so this is all just down to English usage!

When somebody makes a quote, saying "my emphasis" it means that the person making the quote has added the emphasis in order to point-out precisely what it is that they are referring to.

In this case, Per added his own emphasis (in this case, underlining) to point out that he was referring to your usage of the phrase "as low as".

In English, saying "as low as" in a context like this is taken to mean that the person saying it considers the price to be, indeed, low.

So, sorry for this misunderstanding! Now you see where it comes from?

What you wrote was not quite what you meant!