What should lower ball joints for a 1999 Lincoln Continental cost?

Probably no more than $20 to $40 dollars for each if you do it yourself. I usually do them in pairs but if you choose you can do just the one side. You will need a ball joint press to do the job. Some auto parts stores loan them out for free with a tool deposit that is refunded in full upon return of tool. Just factor $20 to $40 dollars per tire.

Quality ball joint cost around 50$.The cheaper aftermarket is half of that.Labor would be an hour /hour and half.