If you want an affordable, disposable, yet smooth writing gel ink pen, the Pilot Super Gel pen is a great choice. Disposable pens in America mostly come in a medium or broad point, but this pen comes in a 0.5 mm tip.
The total length/circumference of the pen is much larger than I thought. This
pen writes real smoothly, but feels too big in my hand. The pen tip is nice and
sturdy however, and the cartridge carries a lot of ink.