You only get a similar effect, not the same, because a true aperture photo blurs "in 3d", which is to say proportional to the z axis. In a PS mod, this is hard to do and likely to look plasticky. OTOH, few can tell, so, you know, viable option.

Oh, and, blur from out of focus is not really blur, but a distortion of focus that is unique to lens design and shutter design. A circular shutter from a 5 blade iris is different from a 7 blade, from a long glass, from the various lens designs and coatings, etc. People choose lens according to how light breaks when lens is out of focus. And some people can tell what lens design you have from the shape of blown spots of light. (a hexagon-like shape is taken with a six blade iris, and the shape of the sides and softness of corners is curvature of the blades)

I'm off topic so I'll stop. Suffice to say, again, there's a reason some DSLRs cost in the small sedan range.