The company's price to earnings is not going to be the best way to measure its performance. Investment income generated from its insurance holdings, gains from equity holdings, etc. is going to cause EPS to fluctuate in a big way.
I like to look at operating earnings for Berkshire. Operating earnings exclude unrealized investment gains/losses, offering a clearer view of its core business performance (insurance underwriting, railroads, utilities, and manufacturing).
When we look to this, Berkshire is trading at 24x its operating income, and historical averages have it around 19x. So on that front, we can see the company is trading at a premium to what it normally does.
That said, I have zero problem adding to my Berkshire position, and it is one I continue to just dollar cost average in to.