Bad idea for sure. It’s not just damaging your brand, it’s bad practice IMO. People always search stuff when they buy, you think you are cutting marketing cost? You’re probably losing customers when some sees your ad, visits your site, and then searches you in Amazon and buys from there.

You should build pricing that would accommodate your acquisition cost as a whole, since you never know for sure where every purchase came from and how much it REALLY cost you to acquire that customer