Hello and welcome to just answer. Are we talking about all 4 ball joints? (upper and lower ball joints on the front left and right sides)?
Ok, the ball joints on this model Dakota is part of the upper and lower control arms and cannot be replaced separately. You will need to replace the control arms which have the ball joints on them. The 2 upper control arms will run about $200.00 each, the lower control arms around $150.00 each so figure about $700.00 in parts. The labor will be about 5 hours, so the labor charge will depend on what the shop's labor rate is. Let's say it is $100.00 an hour, then labor charges will be $500.00. So at that rate, the total cost of this repair would be around $1200.00. If the labor rate is less, then the total cost will be less.
I hope this information is helpful, and if you need more assistance with this please let me know.