This would be the closest alternate: https://www.opticsplanet.com/vortex-strike-eagle-1-8x24mm-riflescope.html
It's a vortex strike eagle 1x6 controls, in a vortex 1x8 body with vortex PST Gen II glass and a vortex HD style exposed turrets. All for $499, you cant loose.
This scope is far superior to the vortex1-8. There is no comparison. The glass, reticle, overall build and reticle brightness are vastly superior in the scope. The closest thing might be the PST 1-6 but this is built to be more of a duty scope vs the PST which is designed to be a competition scope. For the money there is not a comparable scope at the price point
I would also add the Shepherd Scope's reticle is superior to the Vortex Strike Eagle's. Granted, reticles are a very subjective thing. However, in its favor, the Shepherd Scope's reticle is numbered whereas the Strike Eagle's is not. The Shepherd also has a ranging box out to 500 yards; the Strike Eagle does not. And this is coming from a Vortex fanboi who owns a few Vortex scopes which I love for long-range work. But for closer in, I find Shepherd's reticle superior to Vortex's offerings.