I stumbled upon your shopping cart and it looks like it is perfect for our site (also built with Perl!)

We sell gift vouchers up to the value the customer wants so at the moment we have a Paypal Buy Now button with a blank value.

Now what we are also looking for are four shipping options -

Australia: Standard $1 - Express $5
Worldwide: Standard $5 - Express $15

But Paypal doesn't support this and it is a bit hit and miss to expect the customer to add this to the value of the voucher and type it into Paypal.

Can you cart support this by way of a drop down option or a radio check box?

In fact our shopping cart supports such custom shipping rates.
You can design your own shipping rates and their names like in your example. They will appear in form of the drop-down menu.

Regards,
Support @ Shoppingcart.org