I've got two Uniball Zento, one American black ink .7 and one Japanese black ink .5. The third is a Uniball One black ink .7.
I love these pens. They're very good for a cheaper everyday carry. The American bodies are plastic and will take some beating, but don't let them get crushed.
The Japanese Zento has a metal section in place of the plastic and if I remember correctly, it cost me around $17 CAD which makes it the most expensive of the three.
American Zentos come in sets of three for around $15 CAD or so.