Buy it once. Own version 2.

Every license is a lifetime license for SmartChecker 2.x: all 2.x updates, fixes and protocol patches are included, with no subscription. Without a license, SmartChecker reads codes, live data and reports on real vehicles and runs everything on the built-in simulator.

SmartChecker is in private beta. Licenses are issued to beta testers from the waitlist; online checkout opens at launch.

What "lifetime" covers

Every 2.x release: new features, bug fixes, protocol patches and test-format improvements.
A future 3.0 may be a paid upgrade, offered to 2.x owners at a discount. Your 2.x license keeps working either way.
Licenses are locked to your PCs. Mobile Tech and Starter Bundle can move to a new PC once every 6 months from your account (deactivating within 48 hours of activating is free). Pro Shop seats move any time.

Full terms: license agreement.