i know where i can get one for under $75.00 is it worth it or should i just get the PCIII USB.

thanks
Charles

If the unit is in great shape, then it'll be much cheaper than a PCIIIUSB.
The unit will be slightly more involved to install as the 'r' also interconnects to your ignition timing connector (the red one).
It can be a bit tight to get to.

I have a PCIIIr on my SP2 and it runs just fine.
The maps do not interchange between the two units. Different file formats.

I have a PCIIIr on my race bike as well. Runs just fine

Just make sure it works. PCIII's have been known to go bad from time to time. I'm just sayin!