Condition is unknown, so the €3,750 asking price deserves scrutiny rather than an automatic pass. It sits above your recent comparable median of €3,434 and above the €3,592 75th percentile, making it ambitious unless the pair is exceptionally clean, recently serviced, and complete. With no condition details, there is not enough here to justify paying the premium.
The Quad II-Forty remains a desirable valve mono amplifier: its KT88 push-pull design delivers 40W, with a robust power supply, 4/8-ohm taps, and a fast, clear, detailed presentation. That makes it a strong partner for many modern loudspeakers, including electrostatics. Before buying, confirm tube health, low hum, matching monoblocks, original transformers, and included covers, boxes, and cables. At €3,750, excellent cosmetics and fresh valves or service should be expected.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.