Why?

The left is for several games. I don't follow Rockman X prices now, but that seems a bit high?

Regardless, I assume you're referring to the price disparity between JP and US games. There are many factors, ranging from relative scarcity to popularity within their respective regions. Perhaps it is as simple as western collectors being more ravenous and driven by nostalgia, making them only attracted to the US versions. Or maybe they think that only the US version will give them hipster e-cred.

That being said, sometimes things are flipped. Look up pricing of the US and JP releases of Comix Zone and The Ooze.

>lot of mega man x games
>just rockman x

I don't know though, all the Mega Man games for SNES and PS1 are pretty expensive in pal reigons too though. I guess it's just a popular IP to collect