If you want to go full-performance with minimal cost, you need 32 GB of RAM (shared memory file takes 24 GB at the moment and for fastest node it's recommended to keep it in memory) and 1 TB of storage (nvme preferred for speed, block log file takes a bit under 500 GB at the moment). Regarding the CPU, take anything modern and you will be fine. The most important measure is single core performance as it will define how fast can you replay a node from scratch.