In general, this is good advice for dealing with price objection in the negotiation of a premium product. It correctly emphasizes long term relationships over a single sale. It also encourages you to stick to your guns on maintaining margin instead of chasing revenue - critical for premium products.
Where the article loses me is when it advocates telling the customer that you'll lie to help them get a better offer from the competition: "I'll even help you negotiate a lower price by sending you an email underbidding their latest offer." This is ethically wrong. But if that's not a convincing argument, it's also pragmatically a very bad idea. Maintaining integrity is the only sustainable business practice in the long run. Lying & cheating may work once, twice, or a dozen times, but it will catch up to you. Even more pragmatically, you've just told the customer that you can't be trusted, that you'll lie to make a situation more favorable for you. That's undermined your relationship when it's purpose was meant to do just the opposite.
Where the article loses me is when it advocates telling the customer that you'll lie to help them get a better offer from the competition: "I'll even help you negotiate a lower price by sending you an email underbidding their latest offer." This is ethically wrong. But if that's not a convincing argument, it's also pragmatically a very bad idea. Maintaining integrity is the only sustainable business practice in the long run. Lying & cheating may work once, twice, or a dozen times, but it will catch up to you. Even more pragmatically, you've just told the customer that you can't be trusted, that you'll lie to make a situation more favorable for you. That's undermined your relationship when it's purpose was meant to do just the opposite.