The style guides I’ve consulted, including the Chicago Manual of Style 15th Edition, give us a choice of the use or non-use of the comma before ‘too.’ Most tend to prefer omitting the comma.
Here’s a good explanation from Grammar Girl:
• The word “too” is an adverb that indicates “also” or “in addition.” It most often shows up in the middle or at the end of a sentence. Most of the time you probably won't use a comma with “too” because your sentences will be chugging along without needing a pause. So you could say, “I too like reading mysteries” or “I like reading mysteries too.” If, on the other hand, you want to emphasize an abrupt change of thought (1), you do use commas, which, among other things, are used to indicate pauses: “I, too, like reading mysteries” or “I like reading mysteries, too.” In these sentences, you are adding a pause to create emphasis.
There is no right or wrong here. Comma or no comma after “too” is really up to you and the context of the paragraph where the “too” sentence is. If you want to emphasize your thought, you can add the comma to slow the sentence down. If no emphasis is necessary, then no comma is necessary.
http://grammar.quickanddirtyti.../comma-with-too.aspx_______
Examples in dictionaries with ‘too’ at the end of the sentence seem to omit the comma too.
I may have to get with it, update myself, and start leaving out commas before terminal ‘too.’
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P.S. Have you noted that this thread has over 4000 views of it? Isn't this amazing? I think this thread started years ago, but still....I wonder if that number is correct.