Strategies to set up price expectations on sellers. GOOD OR BAD?

[Giancarlo Ameglio]

I heard in one of the BP podcasts a guy whose strategy is to send offers 15% to 50% lower than the price he thinks the property is worth. Then, if he does not get it approved he sends another offer a week after but the seller does not know it's the same person. He is basically setting a price expectation. Do you know anything about this strategy? I think it's very smart but maybe not very ethical what do you guys think?