Hebrew to English Art/Literary Poetry & Literature Song Lyrics

Greetings,

In the musical “סאלח שבתי” there's a song about a man who is in love with a girl whom his father insists that he pays a bride price for.

In the song, a duet between a man and a girl, the man protests as follows:
זה ערך פרינציפיוני, זה הכול
I imagine that Hebrew probably now uses "ערך עקרוני", with its penchant for words of Hebrew origin.

http://www.google.co.uk/search?hl=en&rls=com.microsoft:*:IE-...

Here are some examples of "ערך עקרוני". Which one do you think would make sense in the song? I wonder if the equivalent might not be something like “nominal value”.

But I'm really not sure at all…

All the best, and many thanks,

Simon