While there are many other money plugins we didn't found one matching our criteria.
We wanted a plugin which does not mess up the game defaults (like the ingame displayed money).
So i've just created this small plugin which was matching our criteria.
The plugin is resetting the money to the value of mp_startmoney, once you bought an item.
This can become handy for an Zombie-Server for example.
To download the .smx have a look at the automatic created build:
(Use "download build artifacts")