It is fairly common. We used the sod farm crew a few times when I was working for a contractor. We did the prep and touched it up with a couple of our guys on the site. The rest of our crew was busy doing more productive work. It worked out well as subcontract labor. There is no way in hell it will work out as a stand alone installation.
You might make that point to your prospect. It is labor for laying sod much like separating the labor of applying paint from scraping, sanding, prepping, laying down tarps, and washing the brushes. The rest is not going to happen on its own and none of it helps after the fact.