Are there economy-related commands in clean HLDS? I know that there is
mp_startmoney at very least but I also remeber that there are others like a frag bounty and round winning bounty and many more.
As far as I know (and checked) there is no command to change the game's economy settings on vanilla servers. Those bounties for example are from a plugin.
With certain plugins you can change weapon costs, give bounties, extra bonuses and other stuff, but for vanilla cs you'll have to live with
Here is a reference of existing CVars.