We do landscape lighting as an add-on feature. We do not
markey it independently. It has great profit margins. Most jobs
can be done by one person. Some jobs can be a challenge to lay out IE: runnung under driveways, sidewalks installing transformers in the basement. But, it all comes with time and doing diffrent types of jobs.
We also have the demo battery pack. It works okay. We now use a 10 light set which we set up as temporay. After they have seen it for 2 or 3 nights they can not live with out it!!
If you do plan on getting into this segment, find a certified electrian that can do things on the side for you. Because, sometimes you'll need an outside box run from the fuse box or something else. Always under and hour of work. Try to find an electrian for one hour. They do not want to bother. If you have the electrian then you can cordinate your schedules. I am lucky. I have my wifes cousin who helps me out when I need it.
BTW: lighting can lead to late night appointments. It helps to sell itself if it is dark out side. A friend of mine only does lighting. He works from 12 or 1 PM to about 10 PM every night during the summer.