I went on craigslist and someone is selling the WRT54GL for $20, the router that's linked on reddit. I'm actually considering this....
That's one of the best DD-WRT Routers around. The DD-WRT Project has been stagnant for a while (It's all about Tomato now), and newer routers support were added by the community. I'd say the core DD-WRT project done goofed when they started offering a commercial version of it (which hasn't gotten an update since forever either).
As a router, The GL is a great: It has enough flash storage and RAM to handle the most featured version of DD-WRT. It will struggle on faster than 50mbit internet connections, requiring a small overclock (which you can do through the DD-WRT admin interface easily as selecting a CPU Frequency on a Dropdown Combo Box) and it's only 100mbit (no gigabit lan), but does it's job. And it's amazing with DD-WRT because it allows you to do a myriad of things, like WiFi AP repeater, OpenVPN gateways and all kinds of nice hacky stuff like, for instance, this exploit. It's a great tool to have around.