Quoted from terrapinmark:
I was fortunate/lucky enough to win a Stern Magic NiB game as a prize in a tourney (1981). The arcade valued it at $900
According to IPDB Magic is from August 1979, so it had probably been in the box for a couple of years by June 1981. Probably retailed for a lot more when it first came out. Depreciation on pins was pretty steep back then IIRC. I bought a Bally Paragon (from June 1979) from Aladdin's Castle in December 1981, not in the box but in excellent condition, for $750.