I don't quite follow the data example with the graph example, but if you are wanting the bars to move up and down the axis based on value, then the trick is to create the axis value as a dimension in the load script, eg ...
Data: LOAD * INLINE [ Model, price per unit, quantity, date model 1, 200, 2, 14-01-2012 model 1, 220, 1, 18-01-2012 model 2, 555, 5, 05-02-2012 model 3, 852, 1, 08-02-2012 model 1, 190, 4, 09-02-2012];
XDim: LOAD Model, sum([price per unit] * quantity) as ModelTotalValue resident Data group by Model;
Then when you create your bar-chart, use the new field (ModelTotalValue in my code) as the dimension, and include Model as one of the expressions but just set as Values on Data Points (no bar). Under the Axes tab, tick Continuous for the Dimension Axis.
I think following script is what you're looking for.
flipside, thijsjan told in his message "The price for a model is the average.". That's why I used "avg([price per unit]) as AveragePricePerMonth". And then you can create bar-chart with dimensions AvaragePricePerMonth, Model and expression SumQuantityPerModel. BR
LOADModel, [price per unit], quantity, date FROM C:\Users\alexandr_b\Documents\test1.xlsx (ooxml, embeddedlabels, tableis Лист1);