Here is a fantastic post from houselogic.com that details some typical home lighting expenses!
Outdoor Lighting Prices
The size of your property and the sophistication of your lighting design will affect the total cost of your outdoor lighting. For each LED fixture that is installed, budget $325. In order to scale the electricity down from 120 volts to 12 volts for LEDs, a transformer is also needed, costing roughly $400 installed.
An installed motion sensor security light costs about $150. Depending on the fixture and whether additional wire needs to be routed, installed costs for porch lights and sconces range from $100 to $250.
For a typical two-story, 2,200 square foot home, the cost of contractor-installed exterior lighting might be as follows:
To cover 100 feet of LED pathway lighting, you need 7 fixtures: $2,275
$400 for a transformer
To emphasize the front of the house, add 4 LED uplights: $1,300
For plantings, two LED area lights cost $650.
2 security lights with motion detectors: $300
Cost in total: $4,925
That sum is about the same as the typical cost of a jellyfish lighting system!