OK- ABS ECU's do fail; I've changed several, and they are not cheap new. The most common cause of failure is water ingress into the multi-connector, resulting in corrosion of the ECU pins. (If this is the case, and you are very lucky, you may be able to simply clean the contacts.) The good news is that these cars are getting old now, so it should be possible to find a good used one.
What was the actual error?
MOST IMPORTANT: check the ABS fuse!! And I don't just mean with a meter; if its the type that has a "bolt-on" 50A fusable link in the battery-mounted fusebox, break off the red plastic cover so you can see the actual fuse, and inspect very carefully. They have a tendancy to corrode and fracture, sometimes causing an intermittent problem which is very easy to mis-diagnose as ECU failure, as the error codes this produces are misleading.