Yesterday I read on the forum about videos on YouTube of BlindGuru demonstrating how you can use a blender to make carrot juice and you don't in fact need a juicer. Now, my take on this was, oh, I already have a blender that's looks kind of like one of the four he is shown using-- maybe I can use my blender in the same way! Then I checked out another video and it turns out that the blenders he uses cost from $300-$500. So I posted here that that seems like a lot of money and you might as well buy a nice juicer (mine cost me $40, BTW). A gentleman responded, saying that a $500 blender pays for itself in 3-4 months. I'm not sure how, but ok...
But here's my suggestion: a food processor with a powerful motor costs less that hundreds of dollars, is designed to puree foods more so than a blender, and there you go! Why buy a way-expensive blender rather than an average priced food processor?
But another aspect to consider is that a juicer does much of the straining for you, not all but much. Yes, you can buy a nut-bag and squeeze the pulp but that takes time and effort that the juicer saves you. The juicer has mare parts to clean, but the nut-bag has to be cleaned too.
In short, I am not blown away by the concept of using a blender instead of a juicer, but I did try my mini food processor today on soft vegetables (for gazpacho juice), then squeezed the pulp through a mesh bag I bought at a pet store, and the results were great. The food processor cost me about $25, if I remember. It is small.