"...8 lbs for 34.00..."
Does that $34.00 include shipping?
"...The bulk, is saying that their lye is 100 % pure, the local chem company is claiming their is 99.9 % pure. Does it make a difference as to how close to pure the lye is?..."
Don't get overly hung up on this. The impurities in NaOH or KOH are mainly due to these chemicals reacting with moisture and carbon dioxide in the air. This means that any lye will not remain at the as-shipped purity after you open and close the container a few times. To give you some perspective, NaOH from Essential Depot and from the Lye Guy are 95-97% purity as-shipped, and they make fine soap.
What you will find is that bar soap made with higher purity NaOH will be initially lower in superfat by 2-3% if your soap calc doesn't take NaOH purity into account (and most of the online calcs don't that I know of). If you've been using "normal" NaOH for awhile, expect to find your soap to be a bit different if you switch.
Oh, and I'll also throw in that the word "lye" can mean NaOH or KOH or both, so it's always good to specify which chemical you're talking about. Since you're in the CP soap forum, I assume you mean NaOH, but ya never know....
