I only have one original xbox controller and would like to add more controllers but do it cheaply (as I am a cheapskate

The things that I have looked at are 1. Xbox controllers 2. Xbox to USB adaptors and 3. Xbox to PS2 adaptors.
I already have 4 PS2 controllers lying around and have 2 PS2 to USB adaptors that I use on both my PS3 and PC.
The cheapest option would be to buy an Xbox to USB adaptor which would also allow me if needed to attach a flash disk or keyboard.
What I was thinking was, would it be possible to plug my existing PS2 to USB adaptor into the Xbox to USB adaptor and for the Xbox to recognise the PS2 controller?
It would be cheaper to buy 2 Xbox/USB adaptors than either one original/3rd party controller or one Xbox/PS2 adaptor from where I have looked around.
Does anyone think this would work?