Psychologically buyers like to make an offer so they feel like they have a bargain. You can set it up so it auto accepts a certain amount, That way you dont have to think about it and get tempted to keep accepting low offers, and hence tempted to bump tyour BIN price up to compensate.

Personally I list 30 days BIN straight, then add in offer option as first stage discounting, then after 30 days reduce BIN, remove offer option. After next 30 add in offer again to that price.Just keep cyclling like that until it comes down to a price someone is happy with.

If someone makes a low offer I just counter with my set discount

The other benefit of this is there is no market value for my items so trying to set a price is hard. so I just list everything at same price and let it reduce and find its own value.It saves wasting too much time doing unreliable market research.