Every situation is different. Factors that make a given offer "reasonable" vs "lowball" include:
1 - Whether the unit being offered F.S. was purchased used or new
2 - Age & condition of the unit
3 - Relative rarity and/or reputation of the unit
4 - Reputation of the seller
Let's say I purchased a new headphone for $3K, then sell it after 2-3 months, in perfect condition, relatively little use. It's a much in demand headphone. My instincts in these matters tell me that an aggressive price would be $70%-80% of list, incl. paypal & shipping in U.S. (everyone pays list for this thing when new). Given all that, if someone offered me 50% I'd laugh in their face--a clear lowball. But if I'm @80% of list and someone offers 70%, it's not lowball at all. They've done their research & we can start dickering...
1 - Whether the unit being offered F.S. was purchased used or new
2 - Age & condition of the unit
3 - Relative rarity and/or reputation of the unit
4 - Reputation of the seller
Let's say I purchased a new headphone for $3K, then sell it after 2-3 months, in perfect condition, relatively little use. It's a much in demand headphone. My instincts in these matters tell me that an aggressive price would be $70%-80% of list, incl. paypal & shipping in U.S. (everyone pays list for this thing when new). Given all that, if someone offered me 50% I'd laugh in their face--a clear lowball. But if I'm @80% of list and someone offers 70%, it's not lowball at all. They've done their research & we can start dickering...