The prices of Japanese made and Chinese made lenses are not the same. Firstly, when Nikon move the production of a lens from Japan to China or Thailand, they stop making it in Japan. Secondly, some lenses do not have MIJ versions, e.g. DX 35mm f/1.8G, 50mm f/1.4G, and most of the DX zooms (that are made in Thailand).
If there are MIJ and MIC versions, then the MIJ versions are much older, e.g. AF 50mm f/1.4D, probably 3-4 years older than the MIC versions.
So, you will not find both MIC and MIJ in the shop. And if you find both MIC and MIJ, you gotta ask yourself is that MIJ worth it? You are probably going to pay more, 10-20% more for a lens that may be 3-5 years older. And if you are talking about AF 50mm f/1.8, then it is like 10 years old MIJ vs new(er) MIC, and non-D vs D.
I have MIJ and MIC lenses, but not at the same time, and I personally cannot tell the difference optically. This is from my AF 50mm f/1.4, f/1.4D (MIJ) and f/1.4D (MIC); and the f/1.8 non-D and D MIJ vs D MIC versions. I still have the AF 50mm f/1.4D MIJ, just for the heck of it (and the f/1.8D MIC, and f/1.4G MIC, and the older Ai f/2 and non-Ai f/1.4 - I have too many 50mm).