Randy I bought a new TT last year and my family bought a starter kit as a gift, all of which I use. In the kit was an inline requlator which I see sells of between $15-$20. I soon realized that not only did it restrict pressure but it reduced water flow to about 3-4gpm. You can get a better show with a water pistol.
I recently purchased a Valterra adjustable with guage for $ 52.00 from Camping World and it works very well. See the pictures attached. This was a test so after the short 4ft drinking hose I attached a plain garden hose for the test only. The short hose lets me attach to the campground supply and the lift the water regulator off the ground using a velco strap to attach the short hose to the spigot post.
I can adjust the pressure to 40-45 and still receive a flow of about 12-14gpm. This lets you adapt to campground pressure which varies as some use wells and others use city water.