One of the machines where I host client sites has been receiving 250,000+ uniques/hour every day for months.

Monthly lease on this machine is <$200 USD/month.

It's more how well your LAMP Stack is tuned, rather than your hardware.

LAMP Stack - Linux + Apache + MariaDB (working MySQL) + PHP + Openssl + CMS (like WordPress) + theme + plugins.

Well tuned + cheap hardware performs far better than poorly tuned hardware with unnecessary bolt ons - CDNs + NGINX + Varnish + Load Balancers (to name a few).

Hire a competent site designer (someone who understands end-to-end site design + LAMP tuning) + likely you're server hardware will be run of the mill.

I personally use OVH for my provisioning. They provide hardware + terminal server interface (for crash recovery) + nothing else. No OS. Nothing else.

A good site designer can turn OVH raw hardware into blazing fast sites.