I bought my 850 vac trailer 3yrs ago for about 25k new, straight from ring o matic. Even drove to Pella, IA to pick it up. Couldn't be happier with the purchase, and they are a great company to work with. Haven't had too much maint as others mentioned. Other than a handle breaking off, everything else has been fine. Just have to take care of it like anything else. It does a great job cleaning out the pits, as long as you do them every 6 months or so. That way the mud stays soupyand doesn't get compacted. 1st time cleaning a pit might take some extra work if it hasn't been done in awhile, but the suction on the 850 will impress you. I carry one of those gripper tools ($1 at the hardware store) to reach down into the pit and pick up things that are too big to suck up. Mostly branches, chunks of rock, cell phones, tools, etc.
Feel free to ask any other questions.