If you want a cheaper tumbler harbor freight has a twin drum that is decent and it comes with a few extra belts. I always used mine in the garage so I didn’t have to listen to it in the house. Do your research and learn how to load the drums. You want them to be the right level and use the right amount of grit. I always would add ceramic pellets to the drum also.
You need to be patient because this process is gonna take about a month long from start to finish.
I prefer to keep mine unpolished because the polishing steps will make the rocks a lot smaller by the time you are done