Yeah man, try to drop at least $5k. Seems like a lot, but replacing/rebuilding the engine (including labour) will cost around that much, if not more. Who know what else might break or needs replacing.
You should have mentioned that you found out about the dealer after putting the deposit down, that way we wouldn't bash you
Other than that, the car does look in pretty good shape. Do you have any pictures of the under body? Look out for chassis rails and condition of the suspension, bushes, arms, etc. Looks like the car was tracked (worn after market steering wheel and radiator). Driver's seat and steering wheel can be replaced so it appears to be a low km car.