If you want something router-like, PC Engines apu1d and apu1d4 at $124 and $145 USD are good options, as is the older (but slower, i386-only) alix2d3 at $103.
There are also plenty of micro ATX or all-in-one fanless PCs with dual-NICs in a similar price range. Or dual-NIC Intel NUCs, as well (not fanless).
There are also plenty of micro ATX or all-in-one fanless PCs with dual-NICs in a similar price range. Or dual-NIC Intel NUCs, as well (not fanless).