I'm was recommended by a fellow gamer to try this site for a rust server. Has anyone ever used them before or have any info about them? Are there any surefire hosts out there? I don't want to spend a lot of time searching and just want to get to work. I have a $30/month budget and want to host a 100-150 pop server.

The host is quite good, even the shared plan as well.
3700x should handle 100-200 pop without any problems, and if the protection is enterprise it should handle everything easily - i know few large servers that use it and get close to no attacks through. double check with their support on that though.
BUT i would also get 2 threads or even 2.5 to ensure plugins, unity, oxide etc can use them.

Hey Galapagos, I'm actually the owner of ServerStarter.host.

Feel free to message me on Discord (Ryz0r#0101) and I can answer any questions you have. $30 is plenty to get you a great server!