There's way too many variables so we don't get involved with repair costs here. The leak could be as common as a leaking pan that has to be resealed, or a leaking front pump seal which requires removal of the engine or the transmission. Labor rates vary all over the country. Some shops do just the bare minimum to get the job done because they're looking out for your wallet in the short-term. Some shops go further and replace additional questionable parts to insure a quality repair. That costs more but they're looking out for you in the long-term.
Outer cv joints typically aren't replaced anymore because rebuilt half shafts are so common and inexpensive. If I would ever need one for any of my three Caravans, they can be found for less than $100.00. If just a rubber boot is torn, mine cost $12.00 each and take about an hour to replace.