eBay! ;-)

Just for future searchers, the point of a router is to isolate the network on ONE side (your LAN) from everything on the OTHER side (the WAN).

So, while cascading routers will typically work for internet access, computers on one side of a cascaded router won't be able to see anything connected to the "main" router. Some routers do have the option of forwarding everything through (often called DMZ), but that typically will only work on one port.