This is an ambitious ask at €400: your 14 comparable listings put the median at €88, with the upper quartile at €178. Even allowing for a particularly complete or unusual package, €400 is well beyond the normal used-market band for an Edwards Audio CD player, so the seller would need to justify it with exceptional condition, provenance, or valuable extras.
The appeal is likely the Edwards Audio presentation—compact, thoughtfully made British hi-fi with a more individual, enthusiast-oriented character than mass-market players. At this money, though, the buyer should insist on a demonstration from cold start, reliable disc reading and track access, a quiet transport, working display and remote, plus confirmation of exactly what is included. Without unusually strong supporting detail, this is a pass rather than a buying opportunity.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.