In the beginning I bought lower denominations because the dealer I was using had those in uncirculated condition. I was still thinking in terms of stamp and coin collecting, and not currency speculation. Eventually, when I talked with my dealer, and was told it made no difference in the currency speculation market, I started purchasing larger denominations, and yes, that was for less money per.
But I think a lot of people who are trying very hard not to go into debt buying these, investing only what you can afford, were, and are, buying smaller amounts, not the million dinar at a time, but perhaps a hundred thousand or two, and that means usually having to buy the smaller denominations. Perhaps some dealers will sell you any amount in any denomination combination, but what I have seen are predetermined denomination/amount packages for a certain amount of money. If I were buying with every other paycheque, or with some monthly or quarter yearly insurance or pension benefit, I might be buying the smaller amounts too.
Remember, when it comes to marketing, although we all know the customer is not always right, the customer is always the final consideration. You sell them what they want, when they want, in the format they want, or you don't get the sale.
So, basically the answer to all three of your questions is: they want the business and do what they must to get it. Period.
Edited by smee2, 24 December 2010 - 11:03 PM.