The State of South Carolina maintains a website that publishes all of their spending, grouped by Agency, month, year, category, and expense.
Unfortunately if you want to do any kind of cross-agency comparison, cumulative calculations, or really do anything but randomly poke around, you're out of luck. That's why I started this project years ago in PHP... and finally revived it and converted it to C# so it was more maintainable.
This isn't complete yet, so don't waste your time yet, but the basics of the web scraping are up and running. Hopefully the rest will be wrapped up soon and I'll be able to publish the data on a regular basis as well.