I can't think of any exact match for English's -ology suffix, but, taking a hint from Joonas's studium sapientiae for philosophia (from this link) I'd guess studium valorum or studium pretiorum would work.
Studium, according to my dictionary (Traupman), means eagerness, enthusiasm, keenness, or study. It's not an exact match for -ology, but there is considerable overlap. In my experience, -ologists usually are quite keen on their field.
There are other options for studium, of course. There is disciplina, which perhaps better captures the organized methodology or study of a field. You mentioned scientia, which could also work, especially if by "science" you mean mainly a body of knowlege. If you mean the craft or skill of the field, you could go with calliditas pretiorum. If you are talking about the profession, you could use artificium pretiorum, the "craftmanship of values".
Like with studium none of these is an exact match for axiologia, but if you want to avoid Greek roots you'll have to compromise, or resort to circumlocutions.
If by values you are talking about morals and not economics, then you will probably want to replace pretiorum with morum, finium or valorum in the examples above. Both mores and finis have specialized meaning in philosophical Latin, and valor may as well.