Tenacity is probably not too expensive a boat. My friend has had her for years and does all the work on the boat and engine/boiler himself. He keeps her at home on a trailer and uses an old Landy to take her to rallies.
His grandfather was part of the Aveling Barford company that built steam traction engines and road rollers.
Unfortunately as the early company went bust in the early 1930's no large amounts of company cash came his way.
His father does have a collection of enormous spanners though!
I may dig about a bit and find more steam boat pics to add to that small site.