Ok I think I got it now.
N09D costs 900Y, N23D = 2300Y, N32D = 3200Y, N38D = 3800Y, and so on...
How dumb is that?
Scitron may be following something similar but doesn't quite match, maybe our album's prices are incorrect/without tax? (ex. D28B-0013 > 2627Y, almost 2800Y)