What make of truck Dave, how old, how many km's, what's the age of the pump gear on it. Any service on the pump gear is best done yourself to manage costs. We sold an Isuzu 950 with 250k on it 7 or 8 years old for 80k as a tray no tank or pump gear that was 5 years ago. The bloke who bought it has the Bendigo contract and loves it, it was a great truck. The 950 was serviced by Weststar Trucks where it was purchased. Guess what I'm trying to say is you won't get great quality for 67k imho as an operable truck.
Who's paying your bill and what's their terms, if you know other contractors how long do they wait for payment. How do you secure a contract, buying a truck doesn't always guarantee a contract. Industry compliance requirements can be and are onerous.
Sounds like a great opportunity though my Dad always said there's money in *****, to some degree he was right. Nowadays it's a whole different ball game and the bureaucratic hurdles are always changing. Have you worked for yourself before, there's no guarantees with sewer thats for sure Water Authorities are always looking to cut costs, a sign of the times I suppose.