AMD has committed to restocking to retailers who should be selling at least close to MSRP, but this part is underpriced. We'll likely see it continue to be bought in bulk and resold at a higher price as long as this is true. You're getting what is very nearly a half-price 2600.

3100/3300X will also be compatible with 500 series boards, while it's likely that AMD will drop support for Zen+ (like 1600AF) on B550.

Do you find upgrading low end CPUs to be less expensive overall than going straight to mid range CPUs and skipping the upgrade cycle?

I admit that I'm not as concerned with long-term performance for this system. I've managed to stretch a Phenom II 1055T for more than 10 years now - my interest in PC gaming fell off for a while there - so I've already skipped more than a few upgrade cycles!