You can also set shipping on a "per button" basis. In the code of each button you create, add in this line:
<input type="hidden" name="shipping" value="x.xx">
where "x.xx" is the amount that you want to charge for shipping
you will have to also enable transaction based shipping in your profile.
when you log in to your PayPal account, click on profile. Then click on "shipping calculation", then click the edit button.
There are 2 checkboxes at the bottom. You need to check the one that says something to the effect of "allow transaction based shipping to override the shipping in your profile. (I beleive it is the bottom checkbox).
This allows the code you put in your buttons to be rocognized and used rather that what you have in your profile (the table that you wanted to change).
There is a site out there that will even create the button code for you with the shipping variable already in it. It is
www.techdevils.com. It is listed on the 'Developers' link on PayPal's site.
Patrick O'Neal
PayPal, Inc