If it were me, I'd do prime decomposition on the amounts, calculate their relative magnitude, a boolean value indicating whether they'd been seen before, etc., label a number of training examples, and have a support vector machine generate a classifier.
I'm so glad it is not you, that kind of thing is exactly someone fascinated with machine learning would go for. So many thousands and thousands of crap papers where guys blindly go after machine learning -- and it is mostly always svm --, without even considering other methods, reporting results close to 100% accuracy and other metrics just to find out that they don't even know how to setup training/testing sets, neither have a clue about the features they are using.