For several years I was compensated to work on new products for these folks.
My task was to take the first offering from the manufacturer, break it, record how that happened, and make product improvements.
This process would continue until the folks at SWFA got a product they would judge good enough to put their personal names on.
Some of the abuse we subjected the products, particularly the SS line, both Legacy and HD would scare the average person. Would you take your scope for a swim, park it at the bottom of a lake for a month, then expect it to work? Or throw it repeatedly from a 35 foot tower onto hard ground, kick it down range....and back, mount it and then expect 100% function? We did this and more to the products.
There is the old original SS line of 10, 10M 16, and 20x, which are not the same as the newer HD versions or the MRAD stuff.
The HD and MRAD were in development for something like 8 years before everyone was happy with the end result.
These are not made in the same factory as the legacy scopes.
If you knew where the new units are made then you'd ask "why such a bargain?

For the record, I was never able to break a legacy 10M scope, but I did wear one out. These are still made by the original mfg to the best of my knowledge and are still one of the better buys in the optics world.