Let me be super honest.
I think you're right, though not an 'asshole', more like a selfish person.
But wait, since when does generosity/selfishness or even any morality has anything to do whatsoever with business?
When was the last time a company didn't ask a customer to pay if it was within their legal right to do so?
And speaking of which, what's morality versus legality in a world where Apple or Facebook pay like $65m taxes over $1b revenues silently funneled into other countries by legal means of "fiscal optimization"?
So while I think you're right, from a moral standpoint, and I would probably contact NewEgg myself to actually help them as a company not fuck up again...
I would totally keep the CPU.
I wouldn't post about it on Reddit.
I would probably keep 2 for me and give others to friends who could actually benefit both from the cost-saving and performance (so not my rich trader buddy, not my tech-averse mother either, more like my geeky CS-mate, if I played CS you know).
I'd say keep your generosity for those who actually both deserve and need it: friends or family you love, people in need, charity, education, etc. The guy who fucked up will probably learn a valuable lesson (we all did...) and newegg as a company is only as worth as the quality of their work and the revenue they bring in (bad businesses, whatever the reason, should leave room for the better ones, that's the crude reality of a free market). Newegg isn't a person, it doesn't have feelings, it won't give you things it's not legally forced to or profit-incentivised to do so (e.g. marketing, promotions, gifts, etc.) A company's deeds are never gratuitous, superfluous, irrational. So why should we, towards them? (note: i'm no anti-corp conspirationist, I praise a free market and deeply value economic freedom. but that's the territory that comes with it, it's cold harsh reality, period).
Bottom line: don't try to be more royalist than the king himself (it's a french expression, unsure how to translate it, it means "don't go further than what is asked of you and what actually profits you", hinting at the fact that no one else does that. Only fools, however 'nice'. ;-)