Quick answers
Does one key work in both tools?
Yes. The bundle key is accepted by both K3GP Studio and K3 BFX Editor. You enter the same key in each app.
Does it ever expire?
Never. Lifetime means lifetime — one payment, both tools, forever. No renewals.
When do I get my key?
Immediately after payment. PayPal redirects you to your key page — copy it before you close the tab.
What if I already bought one tool?
The bundle is the best deal if you want both. If you only need one tool, grab it individually from the K3GP or K3 BFX pages.