How much is diagnostic test? How much for tuneup?

I don't know but i do know that they take along time just to change a tire

Wal Mart "techs" are barely able to change tires anymore. They have no actual mechanics and I was told they are not qualified to check the starter draw of a starter nor the output of an alternator prior to installing a new battery. This is basic knowledge and should be done prior to installing a new battery. Example, they sell you a new battery when nothing was wrong with your old one because the drained. They can't check the starter nor alternator to see if a faulty starter drained the battery or a faulty alternator failed to charge the battery. So, you but a new battery and it your locker enough to make it home, bam!, the next morning your late for work because you're battery was dead. SMH

They don't do diagnostic tests or tuneups.

You should contact the store directly as they don't seem to monitor this feed