That is a prime example of 'brand power'. Four plastic letters with 3m tape on the back at the rate of about $50 per letter. The cheapest 'real' emblem I could find is from JZS in Japan who is a huge marketer of Nissan products to the states. They want $125 for the emblem and $36 for shipping to the states ($161), but it will be an original new OEM emblem. Not sure why shipping is so high - perhaps an attempt to post a low selling price and they inflate the shipping to make up for it?
http://www.ebay.com/itm/2010-2011-2012- ... 4106wt_950
However, you're right. The actual cost of production is probably under $10 for Nissan, then they mark it up, followed by the distributor mark-up, leaving the consumer with little choice.