It amazes me (OK, no it doesn't) simple information can elicit so much discourse. Rational and otherwise. The obvious solution was offered early on - set the price that is acceptable and if that is exceeded just move on. Who cares if the seller is using shills, and way too many likely do, since there is nothing for sale at an auction that is likely to have death result as a consequence of failing to obtain it. Such obvious shills as what the OP shows are a PITA but they are not deadly.

Just for the record, I've found GB to be under-responsive to a seller inquiry several times.

have another day
Dr.WtS

Dr.WtS
Mysteries of the Cosmos Unlocked
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