Do you really like the way knots look or are you trying to convince yourself you do? The public perception of knots is negative. Put on a shaft with a knot in it and see what they say about you. Even if your customer likes it or is accepting of it, when the cue is out there representing you it will give a bad impression I am afraid. The value of the wood is meaningless since the value in a cue is labor so discarding it at this point is no loss at all. You don't want to create bad press for yourself or have a customer who has to keep defending you. Worst case scenario is the buyer will not defend you and say something like they got the cue cheap because of the flaw.
Just things to consider. You can do a thousand things right but people remember the one negative even if unfairly.