Building an access router from scratch has its charm and is affordable compared to commercial solutions that support a comparable feature set. Table Table 1.1, “Cost to build” gives an impression of what I paid in 2004. The compact flash card was reused and therefore not included in this table. Buying the wireless parts as a kit might bring the cost down.
|WRAP.1D (2 LAN / 2 miniPCI)||$143||http://www.wisp-router.com|
|Indoor WRAP.1D case||$15||http://www.wisp-router.com|
|Power supply WRAP 12V 1.5A||$15||http://www.wisp-router.com|
|5354 ML Aries 802.11a/b/g miniPCI||$80||http://www.netgate.com|
|Two U.FL to RP-TNC Male Pigtails||$28||http://www.netgate.com/|
|Two 5.0 dBi Rubber Duck RP-TNC Female Antennas||$28||http://www.netgate.com/|
Table 1.1. Cost to build
If you merely want to roll your own Linux based distribution on a wireless router, I recommend buying a Cisco/Linksys access router and tweaking the sources  Another alternative is to buy a cheap motherboard and run a LEAF distribution  or M0n0wall . To get some more performance at the cost of not using a pentium-lookalike, one could use the a MIPS based SBC such as the RouterBoard 500.