"Established 1833 and for decades an American icon Ð Martin guitars are a genuine benchmark by which others are judged."
This quote is from the Martin website. It makes sense to me, as I don't own a Martin, but I can quickly grok the standards that they have established. I would much rather compare my C Fox to any Martin over having it compared with a Sears Silvertone.
Should they be expensive?
Yes, just as any fine guitar is worth paying for.
Are they the best?
No, but they are the benchmark, and even Frederick Martin understands that.