$529.00 is a crazy low price. Cheapest I saw when searching just now was roughly $1,000.00. Can you shoot me a link where you see that price by chance?
Reason I mention it is that I do have a Sightron SIII for sale. (#25006) It's the Sightron SS 6-24x50LR FFP/MOA with the MOA-2 reticle. Still have the box, all accessories, etc.. scope is in great shape. Let me know if you're interested and I can shoot over pics and we can talk price.