Is there any way for the calculator to say ‘call for quote’ when selecting particular combinations so that we can arrange the quote for them?

I am sorry to say that it is not possible to add a warning “call for quote" or any other warning on the calculator pricing engine, when your customer chooses a particular combination. However, here are two ideas that may help:
  1. You can add a text in the long description area of the product page. You can add a large text that mentions something like "Don't see the quantities you need? Call xxx-xxx-xxxx for a quote."
  2. You can create a custom quote form and put it on a custom page to collect quote details from your customer. You can then add a link to the above sentence so that when the user clicks that sentence the will get redirected to custom page that has a quote form.
    Please refer to the article that gives you detailed information on setting up forms Ch. 019. Forms