Is it a base mesh for sub division modeling or game modeling?
  If its for zbrush I would try your hardest to have as few tris as possible. It is possible to have a entire human character that is 100% all quads  :D 
   
   The main reason for this is to avoid poles and pinching when sub dividing and smoothing.
   
   Also if this is for next gen(current gen really) characters. you will need to add at least 10,000 tris :)
   
   The average next gen char on our project is between 15,000 - 20,000 tris. With our main char in at around 35,000 tris. A lot of other next gen games do about the same. 
The base mesh that I use for a full character is about 4,500 tris. and is 100% full quads(which is only ideal for zbrush and not necessary for games). My basic approach is to sub divide it once so it would be at 18,000 tris and then use that (with some tweaking more or less) to be the in game asset.
   Of course starting low poly like you have now and only adding edges when necessary is definitely the way to go :+1: