Mate, im no expert in car sales so dont take my word for it, it was just my opinion. If it was up to me I would make sure you car is worth 20k
. For me the 330i was the best NA non M straight 6 BMW ever made. I think at the time its power to weight ratio was amongst the best seeing as it was an alu and mag block.
But sadly, the way things are BMW have stopped making the engine. and to the mass market its hard to shift. However like i said, if it was to a like minded enthusiast it would be good money all day long.
In regards to the damage, mate you will know soon enough. Hopefully just cosmetic