Badmofo-
I'm actually getting a kick out of people getting bent out of shape over the prices of stand ups lately. Recently, I have been on the sellers side. The most important factor is the buyers. They are the ones making the choice and paying the recent prices. For example, its not like a 1990 super jet is selling for 3000. They are going for around 1300 to 1600(around). Say for example you want to pay $550. One contributing factor is that 1400 is not a lot of money. There is real value there, fiberglass, aluminum, bearings, electrical... and its all together and maybe in working order. Trying to put one together from parts is very expensive. Supply and demand is very important. There are very few stand ups for sale as apposed to sit downs currently. To contribute to that, some manufacturer are limiting or even stopping the sale of them.
Side Note: Another example is the US car market. With sales of new cars down the demand of used cars is up. People want to buy a used car, there are less to go around because not as many people are buying new. Therefore, the prices for used cars are higher.
My experience: If you wanted to buy a used dirt bike, there is a huge supply. I mean, just look on craigslist, there are so many of them. I am trying to sell a crf250 for what I think is a fair price. However the interest is limited. For this reason, if I truly want to sell it. Which would be a good idea before winter comes. (seasons also alter pricing) I need to lower my price. This is an example of how the buyer sets the going price.