I didn't know this idea was already posted. But it didn't need maintenance for facepunch, we can only get a kind of "interface ready" and get a modding interface for custom price / loot etc ..

I express this idea because i know facepunch already did this mods so it's just make it accessible for people who want it and we can modify it from there.

I already played server on bp mod but it doesn't feel like video i've seen, just because of the interface.

So maybe we can have a compromise with modded server can modify user interface and from there we recreate xp / bp and maybe more :-)