Seems to me that the cautions on second-hand shafts might be a little over the top. As soon as you put new shafts in your truck, they are used. What is the difference? I've had new shafts last me 200,000 miles and still good, and others breaking after only a few thousand, so who's to say which of these would have been a good deal secondhand? (Or a good deal new, for that matter!)
Price sounds good to me, and if there's no evidence of twisting (and if you are sure they are the brand they are being touted as), then there's no particular reason to imagine they will fail any sooner than new ones.