The cost VZW notes for calls is the per-minute rate for calling/answering any call regardless of where the other party is, while you are located in that country. Calling a toll-free Dutch number will still cost the per-minute rate as calling a Dutch mobile as calling a French landline as calling a US landline as answering a call from Botswana.

Also note that declining a call will result in double the per-minute charge while the person leaves a voicemail. You get charged the per-minute rate for Verizon to forward the call internationally from the US to Germany, and then the per-minute rate again for the German roaming partner to forward it back to Verizon's voicemail system. This is how all mobile providers work; it's not just Verizon.

Also be careful of data roaming, which can very quickly become obscenely expensive. It's easy to rack up a few thousand dollars in data roaming fees.