Indeed. But in addition to decent photos, dealers should offer at least 14 days upon delivery for cancellation which I think is the law regarding distance selling.
I agree that it is very annoying if defects such as hairlines, verd, past cleaning, artificial toning, etc are not mentioned. Being able to return a coin is not really an excuse not to mention such things.
I do get the impression that some sellers are very accurate with grading lower values coins but are more generous when grading high value pieces. It's up to them but I would rather people don't do things like that. Different dealers have different reputations.
There is nothing wrong in my view with sellers aiming to make say 100% profit compared to what they paid in auctions. If a dealer is on the lookout of real bargains on auctions and sell at high profit margins, then that is their choice. Sellers aiming to make about 30% profit margin would find it much easier to buy stock and will have much faster turnaround times. Just different business models and one buys from sellers sharing his philosophy.