> Absolute cheapest DDR5 128GB kit around is 2 sticks of 5600 64GB for $2k.

That's not far from the bundle deal above, once you subtract the $700 CPU.

If you really need 128GB the 5600 kit is fine. Having 208MB of total cache on the CPU means the real world difference between a 5600 kit and a slightly faster kit is negligible in most use cases.

If you don't need to upgrade then clearly don't force an upgrade right now. I just wanted to comment that $4K for 128GB of RAM is a very bad price right now, even with the current situation.