It sounds like you are merging just one record, hence the reference to wasted labels, as mail merge always starts from label 1. Maybe a different approach is called for.
You could consider
Envelope or label add-in for Word which doesn't use mail merge but can print one or more labels from an Excel data source. You can select which fields go on the labels and which label to start with.
It takes a bit of effort to configure to your requirements, but then is simple enough for repetition.