Tensioner failed, valves bent (2000 s80).

Which would be better, Valve replacement or a used engine?

1. I heard you could just buy thecylinder head and valves pre-assembled from Volvo for around $1,200 (not sure if that is the real price, it was listed here in the s-80 forum at that price).
Anyone know aprox. labor to remove old and replace?

Or 2. Replace engine with used engine 108k miles, for $1,600plus labor (approx $750) = $2,350

thanks for any advice...