Active adapters of the sort you might need probably start around $70 and go up depending on the ports required. To get a 4k hdmi 2.0 to dp adapter would cost like $120+ for example.
I'm sure someone eventually made one to address the market need, and $120 sounds like a fair price given the complexity. It wasn't available when I needed it, and it doesn't change the fact that Sony just up and dropped support for old displays.
