Fact: there is no such thing as "free." Never was. Never will be.
The dealers who do that do not take cash out of their own pocket to provide that starter kit. They charge you for it, and personally, I'd prefer to buy my own. No such kit was even mentioned when we bought our rig. Consequently I went out and bought my own pieces in the quality level _I_ wanted and at the price _I_ could get them.
So, it's a dealer option, not standard at all.
And yes, the little $15 water pressure regulator is crap. Don't fall for one. Spring for the $70 high quality one. You'll be glad you did. And when you use it, put it on the spigot BEFORE your water hose. I made the mistake of putting it on the trailer AFTER the hose, once, and the pressure was so high it caused the hose to rupture.