I'm working on
https://runs-on.com, a self-hosted solution to get 10x cheaper GitHub Actions runners with support for Linux x64 and arm64. This month I've been refining Windows support and hopefully this gets fully shipped before Aug 31st!
We're really looking forward to Windows support - I don't think any Actions runners vendors supports Windows at the moment and we were looking at building our own runners as a result, but if this launches soon, we'd be very keen to try it out!
Thanks, I'll ping you when it's available!