I'm just getting started with landscape lighting, and I've read many posts about typical costs to the homeowner ($200 per fixture installed). What are the typical costs to the INSTALLER per fixture? What are the other costs involved in an install (wire, transformers, etc.). Do the installers normally buy the fixtures for wholesale and then mark them up to retail price when they install? Gross sales figures are nice to know, but in the end meaningless without a knowledge of the costs involved. Thanks!