100G, probably not unless you are extremely wealthy and you have a burning desire to be destitute. 40G is definitely doable for a homelab. Used 40Gbe adapters a

100G, probably not unless you are extremely wealthy and you have a burning desire to be destitute. 40G is definitely doable for a homelab. Used 40Gbe adapters are roughly $200 and DAC cables are < $100. QSPF+ Switches are much harder to find used and/or cheap though. This means that p2p solutions or ring networks are generally preferred unless you are wealthy. If you want fiber, which you don't need for a homelab, you pay the prices listed above.