Is €720 the kind of number that makes you stop and pounce, or does it only look fair once you check the condition and completeness? For a Sharp GF-666 in good shape, €720 sits around the upper-middle of the used market rather than looking like a steal; comparable listings have landed roughly from about €140 to €250 in rough-to-average condition, while cleaner, collector-facing examples can push into the €700 range, so this asks fair-to-strong money rather than bargain money.
That said, this is a cult boombox with real collector pull: big presence, classic Sharp styling, and enough nostalgia to justify paying up when the unit is clean, complete, and working properly. The upside is strongest if it’s original, untouched, and includes the usual extras like correct antennas, battery door, or box; at this price, you want proof of full function, especially both decks, radio, and battery operation.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.