Firewire is not expensive and it will work just fine.... .... I don't know where people get information from sometimes....
Transferring data between 2 PCs is simple with firewire.....first you'll need the cable.
You'll have to have a port on either PC. You mentioned that you have a cable but you have to make sure that the 1394 cable has the right ends on it. PCs (and firewire PCI cards) generally have a female 1394 port. If your 1394 cable has two male ends on it and your PCs have 2 females (1 on each) then you are in good shape. Literally just plug them in.
BTW, if you don't have at least Win2k or XP on them....it won't work. I think WinME works also but....yea whatever.
Anyway, once the two computers are connected you are going to go into your network properties for the firewire port (just like you would for the typical networking (Cat5/5e/etc) ports. Adjust the properties of the firewire network on each computer to contain an IP address (one for each computer) ... to get it working, you simply need an IP address and a subnet mask for each....nothing else.
PC1: IP = 192.168.1.10
Subnet Mask = 255.255.255.0
PC2: IP = 192.168.1.11 (The 2 PCs must be different.....just use these)
Subnet Mask = 255.255.255.0
Or just let them configure their own address.
The firewire network and fire sharing will work exactly like a typical Ethernet network will......so disable your software firewalls, enable fire/print sharing on both on them/etc.
Here are some tips....i don't really feel like typing a whole lot and reinvent the wheel that someone already got turning....so here...
WeetHet - Network - Using FireWire to connect 2 PC's