I'm pretty sure paypal/gir bot take care of getting the address for you. When someone bought my Paul+Dragon Companion Set, I got this email from firstname.lastname@example.org (I omitted the personal details for privacy):
Congratulations Nicole, you've made a sale!
name_of_person has purchased your item, "Paul + Dragon Companion Set!" for $85.00.
permies fees: $0.85
Paypal fees: $2.77
Your profit: $81.38
Yeah, the shipping options in the digital market could really benefit from some fine tuning. Currently, there's only two prices for shipping: US, and international. International shipping has to be equal to, or more, than US shipping. This stinks in a lot of ways, as even shipping in the US can cost different amounts depending on how far away it is (Shipping from Seattle to Portland, Oregon costs a whole lot less than shipping to Maine), and international shipping costs vary based on the country.
In other words, there's no way to only ship to one country unless that country is the US.
When I talked with Paul about this back when I listed my fairies and dragons, his perspective was that it wasn't worth expending the resources to improve it unless there was enough demand for physical items... and right now, there just isn't. I'm hoping that will change, though! I'd love to see a "cart" option, too, where people could add multiple things from one seller and then have shipping calculated, that way I'm not refunding someone money if they order, say, 2 fairies and a dragon and two magic staves.