If you have a digital camcorder with a pass thru mode, you could do that instead. It allows the analog input from AV cables to be output thru the firewire output on your camcorder.
There are a wide variety of them available, some are in the $35 range I believe. Search Newegg for deals.
I went a little higher end and got the Canopus ADVC 110. Its capture is awesome. About $150.
You could also get a DVHS deck and capture in HS mode which creates a m2t file you could output via firewire. Not a mainstream solution but you get a DVHS player/recorder.