There are many variables here, including the scale of the event, and experience of the photographer. In general, a decent wedding photographer could make between $800 - $1500 per wedding.
It depends on the type and number of the pictures you want to be taken. Normally if the photos have a lot of computer effects they will be more expensive. You should do some research as well. I for instance paid 250 Euros for 100 pictures, having also served the photographer a meal.
