Just thinkin out loud here
A - I've got no idea what determines the order in which the prints in "my collection" appear, but there seems to be something going on there. How about a "sort by" field where we can sort our own collections by things such as print title, artist, year, average original price, average secondary market price, class, etc? Maybe include a little checkbox to save this preferance as well.
B - Adding another power or two into the equation that calculates price history. This should be a simple one. An example is
http://www.expressobeans.com/show.php?id=16722
For the sake of arguement, with the straight line equation of y = mx + b, you get the false impression that the poster value will eventually reach zero sometime this spring. Increasing the order in which the computer program uses to calculate the "best fit" equation to a third or fourth power would produce a curve that's more of a parabola and more accurately show that the average price of this print is trending back up.
If this is incorporated, it might also be a good idea to have the best fit line a little thinner and plot on top of the individual sales points instead of the other way around, so the trendline doesn't get lost in the data on pieces that sell back and forth a lot.
Two site suggestions
huh? Couldn't people just look at the price history to know if a print's value is increasing or decreasing?A - after looking at it a little more i figured out the posters in "my collection" are ordered by year, then sub-sequenced by print title. I still think it'd be cool to be able to change the order as I originally described.
B - here's a slopy graphical example i threw together. same data points, i just asked excel to calculate the best fit equation using a higher order. The curve is just more interesting (to me, at least)
B - here's a slopy graphical example i threw together. same data points, i just asked excel to calculate the best fit equation using a higher order. The curve is just more interesting (to me, at least)