How do you figure that? You can rent the exact same server as a dedicated server. The difference is, you have no capital outlay up front, you don't need to ship and rack it or replace broken parts and there is only a month-to-month commitment.

The boxes with lots of disk and memory are much more expensive when rented vs buying. SSDs are super expensive to rent, for example.

I made a Skylake Xeon system with all enterprise components for $2k. You can't even rent Skylake Xeons anywhere right now.

I've never had problems ordering custom hardware from my dedicated server providers. At worst, all I've had to do is pay a one-time fee for a particular component. SSDs have never been a problem. Neither has any Intel CPU.

It of course depends on your provider.

Rent vs buy depends a lot on the circumstances. Maybe if your requirements don't change and you don't upgrade your server hardware it's cheaper in the long run to buy. However, when I've kept a server for more than a year, I've always been able to negotiate a discount.

You didn't post your config, so I can't tell how exotic your requirements are.