A a $5/month VPS from DO/Vultr/Linode/etc (1 vCPU, 1GB RAM, 20/25GB SSD) should be good for quite a while! I have one from Vultr and I run multiple things in there, including lemmy.pt, and haven't ran into any resource issues. The instance is small, but Lemmy doesn't take up more than 350MB (server, UI, postgres, pict-rs and email relay), and CPU basically never goes beyond 20% (idles at 5/10).