We are not to judge thrift solely by the test of saving or spending. If one spends what he should prudently save, that certainly is to be deplored. But if one saves what he should prudently spend, that is not necessarily to be commended. A wise balance between the two is the desired end.
Sanctification means more than being freed from sin. It means the deliberate commitment of myself to the God of my salvation, and being willing to pay whatever it may cost.