Op, he wasn't responding to your question. He was responding to the absolutely terrible advice to lower your prices.

And if you don't have a simple answer to why you deserve the rate you are asking, it does seem like it's your first day of freelancing.

Now to answer your question, "my rates are accounting for the experience and skill set that I bring to the table. This allows me to effectively and efficiently complete my job in a manner that returns the results you desire. Feel free to explore other options but in my experience, you get what you pay for with skilled services. Those charging less than market value for the same services generally provide substandard work otherwise they'd be asking the market rate." (this is assuming you are asking for what the market has determined to be fair wage for your ability and experience.