Surplus Computers offers the refurbished Netgear SC101 Storage Central NAS Enclosure for $29.99. With around $11 for shipping, that's $26 under the lowest total price we could find for a new, factory-sealed unit. (We saw the refurb in February for $14 less, since expired.) This enclosure holds up to two ATA6 or above IDE hard drives and features an Ethernet connection.
A 90-day warranty applies, although it's unclear who supports it.
Netgear Ide Network Storage Central Sc101, a similar product, is available at these stores