One question, though:
How much would be the boundaries around the (Category) Average
for the classifier to place a Product in the respective class (bin)?
In your example, comparing 15 to 14 would give the 'IN' (Average),
whereas 20 would give the 'Above', and 8 would give the 'Below'.
What about 16, 17, 18, 19 (or 13, 12, 11, 10, 9 for that matter)?
In reality there would be hard thresholds, i.e. <14 = below, >14 = above, 14 = average