I seem to be experiencing some difficulty in getting the types of sort I expect when I try sorting by "Progress", "Price (Highest first)" - has something changed ther recently ? 
I would have thought that http://www.logos.com/product/9847/critical-and-exegetical-commentary-on-the-new-testament-21-vols at around 96% should be listed first among "Progress" , and that
Classic Commentaries and Studies on Revelation (27 vols.) http://www.logos.com/product/8522/classic-commentaries-and-studies-on-revelation at $160 would show well ahead of those currently at $80 
(Using IE9 with latest updates, although IE* seems to be giving the same problem results)