Recently, I discovered just how cheap it is to finally fixed the lack of wireless coverage at the top floor of my home... at just S$30! The solution? A second hand WRT54G v2.2 wireless router running Tomato configured as a secondary AP.
Originally, I had wanted to run it in WDS mode but realized that I have a problem with placement (its out of reach from my primary AP signal) and didn't like the fact that throughput will be halved.
Luckily, I have a HomePlug network in place hence I just replaced the LAN switch in my study with the WRT54G now doubling as the LAN switch plus secondary AP hooked into the home network via the HomePlug. (Configuration details of my WRT54G can be found here.)
There are plenty of used WRT54G wireless routers for sale on local forum marketplaces like HWZ and VR-Zone and S$30 appears to be the going rate. Do note that if you wish to run a third party firmware (like Tomato) on the WRT54G, be sure that you are getting the hardware revisions 1 to 4 only. Anything higher is not supported.