Another thing is will you be using this as a highway or city driver? It may not be fine going stop and go in a 380, but OK in 450/560. On the flip side, you might get better mpg with the smaller engine and power won't matter on the highway.
I would say that that price is a decent price and would take it if you like the ride. That mileage is really low, like a brand new car!
'89 420 SEL
'90 300 SEL
'68 Olds 88 Convertible
'84 300 SD (sold it)