between $0 and the cost of 2 complete wheel hub assemblies.
The hub assembly has the connector to the WSS right on it. Usually your hub is still fine but the wires or the connector deteriorate. This causes the ABS and trac control to stop working.
Aside from scanning the car to see which side is defective, your options are:
1) try cleaning the connector with contact cleaner (I got 4 extra months out of my GF's 98 regal GS with just that).
2) remove the faulty hub and resolder the defective wire/connector
3) R&R defective hub (or hubs if it is both, but that is highly unlikely)
If you are getting close to 100k miles, your hub bearings are about to crap out anyway.
I suggest buying the SKF brand. It is one of the last ones made in the USA (by Chicago-Rawhide)
BR930548K BEARING & HUB ASSEMBLY Wheel Front;w/Metal Clip
expect to pay around 130-150 US for JUST the hub. Crazy, eh? as for labour, expect a few hours. You can do it yourself though. There is a great write-up somewhere on here. It isn't that difficult.
some have reported buying SKF and seeing "made in china" on the box. I JUST bought one last week and it was made in the USA. Unfortunately guaranteed only 1 year, same as Chinese crap. I have trouble bringing myself to replace a perfectly good hub just because the WSS is faulty, but it is my GF's car, and well...you know.
Timken is also made in the USA.
Dynapak is made in China. I'd stay away.
Anyhow, welcome to the forum. Take a few minutes to go post in the welcome section (this one) with details about your car. It really helps when diagnosing problems. Also, take the time to create a signature with relevant info.