mwave offers the refurbished TRENDnet 10/100Mbps PCI-Express Ethernet Adapter Card, model no. TE100-PCIWN, for $1.99 with free shipping. That's $2 below our June mention of a refurb and $6 under the lowest total price we could find for a new unit. It features one RJ-45 port.

A 60-day warranty applies, although it's unclear who supports it.