As mentioned, KLM is the responsible airline since they were last to handle luggage. I've never heard of a $60 limit... but don't know how KLM handles that. Usually it is a 'reasonable cost' for necessary items and depends on how long the delay is with getting your bags delivered.

Your bag claim tickets and Delta tracker should show if it was scanned when loaded on the plane from MSP-AMS (most likely was ok getting there)... and if the bags were on that flight then the issue is at AMS and the bags are probably still there with KLM. There are multiple flights daily from AMS-OSL so I would expect KLM can deliver your bags quickly.