Primal Amulet

Primal Amulet's last ability triggers once you've completed casting a spell. Notably, you can't use Primal Wellspring to pay for the spell that gives Primal Amulet its fourth counter.

Primal Wellspring's delayed triggered ability can copy the spell even if that spell is countered before the ability resolves.

The copy will have the same targets as the spell it's copying unless you choose new ones. You may change any number of the targets, including all of them or none of them. If, for one of the targets, you can't choose a new legal target, then it remains unchanged (even if the current target is illegal).