That's exactly the instructions I used. Basically, the idea is to use a PC and a modified version of the PC flasher to flash a fake Mac ROM to the card. Then, you install the card in a Mac and use the ATI flash updater to install the correct ROM.
Needless to say, you need access to a PC and another PCI Mac video card. Also, although the ATI flasher for Mac should run under OS X, you'll have a lot less issues if you boot under 9.x. (In my case, it seemed like X would not boot to the desktop while the card with the fake ROM was installed, but had no problems booting 9.2.2.)
Personally, I'd say that the prices for the early ones are already there. Back in December, I almost picked up a similar box for $10, but would have had to get it home from the in-laws house in CA. I held off as long as I did only because I didn't want to pay shipping.
John