If it's a 2006 chassis, it's a 5cyl inline engine which is the best Sprinter engine out there. It can be a 2007 motorhome on a 2006 chassis. Not unusual.
The 5cyl can burn basically any diesel fuel, doesn't take a special European spec oil like the 2007 on up chassis, and doesn't have all the emissions equipment that the newer ones do that cause boo-koo problems.
If it's a good price, been taken care of etc, grab it, it's a gem.
We recently saw one of these 2007's that looked brand new and only had 32k miles on it. The couple had just retired and bought it from some friends of theirs so they knew what they were getting. It was a beauty!
Bob & Sharon
Eastern Kansas
2013 Winnebago ERA 70A
Class B Van