Never heard that in a discussion. I thought it was all about comparing like to like. The OP didn't say "for reading emails". Especially as he gave the example of 100% Office compatibility (Office 2011?).
Or you could compare live time value. I've broken several Thinkpads in a small amount of time, my wife uses a MacBook for more than 5 years with the newest operating system and applications.
Or, if you need email, only use a phone. Or if you only surf the web, buy a tablet. Or if you only do small amounts of web and email, don't buy anything at all and go to a free library. It depends.
But the argument was that a Mac laptop is much more expensive than a PC laptop for working with Office. Which it is not to my knowledge.
If you don't need it, don't buy it - no argument there.
http://configure.us.dell.com/dellstore/config.aspx?oc=bqct14...