Really nice reply, Suzanne, and a terrific perspective on the art auction biz. I guess the real secret (as with anything else you buy) is to know the market, which you obviously do.
I did hear an interesting take some years ago from someone heavily involved with "art as investement." He said that if something is under $500, and you can afford it, and you REALLY like it, you should probably buy it, not because it's necessarily worth the price, but because you want to have it in your home and want to look at it. He went on to say that anything over $500 should be the product of reasonable research and comparison shopping, because at that point you're really talking about an investment, even if you love it. This was one man's opinion, and it was several years ago, so if you buy the concept I guess you'd have to inflation- adjust the $500 a bit.
We've never bought art on a ship, because we don't trust ourselves in an auction enviornment where we don't really know the market, but I've always thought the advice of the investment guy had some merit.