How can I have the total of products to be sent to Paypal total field?

The form offers multiple choices many of which have price tags ($25, $50, etc.). Is it possible to place calculation routines behind the priced options and for the form to automatically add up the price tags on the options selected, then place the total in the total price tag window? If it's possible, I don't know how to do this.

Yes it is possible.

1. First you need to add calculation values to the fields:

2. Then you need to add a Form calculation field:

3. Add the fields you wish to sum:

4. On the Paypal payment tool select "get amount from: "form calculation field" ":

You can test and clone the demo form:

http://form.jotformpro.com/form/50704190599965? 

Let us know if we can assist you further.