Yes, but those are also 50mm lenses, and the precise reason I avoided putting in an f/number The f1.8 is also much cheaper for those buying on a budget.
My point is that if a 50mm lens is a must have for portraits on crop (which it is), even though the f/1.8 is very cheap, the plastic build quality and pentagon shaped circular highlights are limiting factors. As such, the Canon or Sigma f/1.4 might be worth considering as they are better built and produce more pleasing bokeh. Also, the difference between f/1.8 and f/1.2 might be slight, but it's not just about maximum aperture - bokeh, colour rendition, flare, barrel distortion, corner light fall-off and AF speed all come into play with the more expensive versions of the 50mm.
For the money, the f/1.8 is worth having, but the f/1.2 trounces it in all areas, which it should being over 12x more expensive. The canon and Sigma f/1.4 offer significant improvement for not such a massive increase.