postage for pocketfold invites

Hi Ladies! I'm in my first proof for my invites by Tessa! So far, I love them!! Here's a link to my proof: http://***************.com/Portfolio/In-Progress/EricaB/index.html


I'm just wondering how much postage would cost. If anybody's done a 5 x 7 pocketfold with a ribbon, could you just give me an idea on how much the postage cost for each invite? I am really trying to keep my costs down.... TIA!