Free: Contests & Raffles.
A used Leupold 12-40x60 on eBay. They're going for right at $500. Made in the USA. I don't believe that can be said for any other spotting scope. I don't think you can do any better for $500. Some will suggest Vortex, BUT... They're made in China!
I haven't seen one that I would find worth carrying at that price. If that's all the no y you have, spend it on a nice set of binos.
Curious on the difference between the hd vs non-hd viper. Dad has the HD. $490 has me thinking about one. We also have the ED 50 by Nikon, a little more than 500, but unbelievable for a small spotter.