[Inspired]

Low voltage or line? I'm guessing low voltage.

Home depot or quality light fixtures? Just my opinion, but nothing you can buy in a home center store like Home Depot or Lowes is worth installing as a contractor. Not if you are planning to warranty them.

As a landscape contractor 7 years ago my average installed system cost retail ran about 155.00 Per Fixture. I would use that figure to shoot people a ball park estimate up front and make sure we were on the same page. I would never use it as a bid price.

That means an average 10 light system with transformer, timer, photocell, wire, waterproof connectors, lights, install labor, final adjustments, and bulb exchanges would cost 1,550.00 before tax.

That was 1999. Obviously I would charge more now. Also the cost of fixtures and transformers is a very large portion of a lighting job. We only installed the higher grade fixtures like:
Nightscaping
Focus
Vista
Hadco
FX
Etc.

I arrived at that figure by experience and keeping close track of my costs installing systems over a few years, including keeping track of warranty issues and what caused them.

All that said, never just accept someone elses figures and run with it. You really have to know your own costs, and abilities.

Hope that helps you somehow.
Bill