190 2.3-16v timing chain question

[reinier]

Ok, how stupid is it to only put a new timing chain and rails/tensioner on a 190 2.3 16v which has done 200.000 km/ 120.000 miles, and leave the sprockets of the cams an crankshaft where they are?

Because the chain is not very expensive, en sometimes breaks (read somewhere also about failing tensioners (are they also relatively cheap?), but the sprockets/gears (what is the exact word?) are expensive (2-300 euros a piece)

Its for a car that wont be running much, but dont want to take the risk of a breaking chain.