This is a seller’s market only if the exact model and configuration are especially desirable; otherwise, €2,999 is clearly ambitious. Your 12 comparable listings put the median at €1,653, with the 75th percentile at €2,469, so this ask sits well above the normal used-market range. At this money, the listing needs unusually strong justification—top-spec 880-series hardware, exceptional length, or near-new presentation.
The Classic Legend G9 range is well regarded for its low-capacitance design, refined silver-gold conductors, smooth tonal balance, and strong resolution and imaging. The G9 generation, with its advanced insulation and shielding, can be a worthwhile upgrade in a revealing system, and clean condition helps. Still, without precise model, length, termination, packaging, and purchase provenance, €2,999 is difficult to defend; negotiation toward roughly €2,000–€2,400 would make the opportunity substantially more attractive.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.