Experience is the best guide, but if you have a Red Book it might not be a bad idea to look through it.
Let me mention again that I don't know that it has been cleaned; it just has that feel from the images that have been provided. Now, does that make the seller a bad dealer? Well, if it is cleaned then I would imagine that a full time dealer would know this, but depending on what you paid you still may have received value commensurate with sales price. Truly, I am more of the mind that it is the responsibility of the buyer to have a good handle on what they are buying before money is exchanged.
What type of lighting are you using for your shots? This could be your problem. The coin still does have the cleaned feel that Tom is talking about. Try taking photos of the coin, but this time, if you can try to use something like lamps. I use three lamps to take my photos, all the lights hitting my coin in different spots, if you can, get under a good light or too, with creating a hot spot, or overexposing the coin anywhere. Also, make sure you are using Macro on your camera. (Setting in which focus is set to get details. Should look like a flower and say Macro, depending on your camera) Also, even if this coin is cleaned, he is still a good dealer, no matter what your age or level of knowledge, you shouldn't have to be told everything from your dealer. You have to bring some knowledge yourself to the table, and the RedBook won't tell you everything. I think buying different grading books, and looking at PCGS Photograde, along with getting books that are specific for the type of coin you are buying are your best defense against buying any kind of altered coin. Also stick around here and ask all questions you have. You'll learn over time what some signs of a cleaned coin are, as you learn more about the regular patina of a coin and the marks that go along with that particular grade.
you got to understand dealers have a ton of coins. you can't expect them to automatically remember details on each one. that is why they let the costumer examine them. most of the time they just pull the coin out and hand it to you. now if you strait up asked him, is this cleaned? and he said "no" when it clearly was, then its sort of a debate. but really not even, its his coin at that point he can think what he wants, and you can still walk away. i am not pointing this at you, but its easier to be a bad costumer then a bad dealer, when it comes to buying coins. and this is coming from someone who has had horrible experiences with dealers.
Hunt, listen to Tom B! He is a very knowledgeable collector. I agree that it looks to have been cleaned. You need to get more light in your images, and the light source should be set at an angle to the coin. The camera needs to be directly over the coin, not at an angle. If the lights were directly over the coin, it would just bounce back into the lens. Also, if your camera has programmable settings, see if you can't adjust the photo size to about 640x480 (e-mail size), but if the camera doesn't have this setting, you should resize it before posting. Chris
Rule #1: If you have to ask if it has been cleaned or polished, then it has been cleaned or polished. Rule #2: See Rule #1.