Well, thats what I was thinking. Besides potentially I could be looking at a rebuilt diesel as well. But then, as long as you don't do it yourself - there is probably a very significant cost to pay to a mechanic.
So far the biggest thing I've done is rebuilding Volvo diesel cooling system (I HATE them, really!) - that does not rise to level of real engine work, so I am not sure I am qualified to do actual replacement just yet