I never owned an A-Bolt III, but I have owned the original A-Bolt, A-Bolt II and X-Bolt. Every one has been a tack driver right out of the box. My current go to rifle is the X-Bolt Stainless Stalker in 7MM Remington Magnum. I will never own another brand.
You can still find the A-Bolt II if you search the net. It is now a limited edition rifle. I bought a Stainless Stalker in .270 for my wife in 2013 from Bass Pro for $499. It was part of a special run for their deer camp promotion.
In any case, I would spend $529 for an A-Bolt III just to test it out.