The 401 is technically the better turntable than the 301 but has always been the less cultish (and cheaper) of the two - a distinction the price gap keeps visible.
Idler-drive turntable: the idler wheel, main bearing and motor mounting decide the price far more than cosmetics. Check the platter spins without rumble at both speeds and that the original plinth/arm are present (a missing SME arm or a non-original plinth can halve the value).
Marks that can be entered for this maker: Serial number, Model / catalogue number, Model / catalogue number, British capacitor code (Hunts, Mullard), Japanese capacitor code (Nichicon, Chemi-Con, ELNA), EIA component code, Chassis / platter stamp, Version & era marker.
Nothing predates 1965; components only push the date later.
Sold-price aggregates are not collected yet, so the archive gives no figure — condition, originality of the transformers and a documented recap move this model more than any list price.
Evidence: serial-number-decoder.com · Stereophile — EICO HF-81 review · +1 more