I don't see any obvious cleaning evidence. Possibly the coin was dipped white long ago and has since toned to it's current color. The scratch is old and not too distracting IMO.
It's hard to find higher-grade bust dimes with good eye appeal. I agree this coin has EF40 or EF45 detail. If it could slab EF45 at PCGS I'd call it a good deal. If I paid $250 and it came back from PCGS in a bodybag ("scratched", "altered surfaces", or "cleaned") I would be unhappy.
If you would be interested in having it graded, maybe the seller will guarantee that it will slab. You could ask!