Watch craigslist, I frequently see them on there. Got mine for $100 and I needed it. If I put the tailgate down, I must be perfectly straight with the 5th wheel because I had only about an inch to spare.
For me, it was just easier to get a V-notched gate and forget about it. One less thing to think about and one less expensive thing that won't get damaged.
2005 GMC Sierra SLT CC/SB with 6.6L Duramax/Allison
2002 Automate 5W, 32 ft, 13,280 GVWR
Valley Glider Hitch
I frequently RV alone so any thing that can make my hook up/set up easier is right up my alley. Putting a tailgate down/up is an extra trip out of the pickup cab I would prefer not to make. I also use the pickup bed for hauling "stuff", and picked up a 4ft piece of angle iron from a big box hardware store, and hose clamp it to the top rail of the V-gate when I want to load an ATV or something on that order. To each their own, but having the V-gate makes my life easier when camping.