As for the paper I used papercircle.ca They are a canadian company and their prices are fantastic! They were so great to work with and shipped really quickly. I checked and they do have pink metallic cardstock.
We used 1 cartridge of ink and we did 50 invites. We have an HP inkjet printer. As for cost it actually is pretty decent. In order to make our invites we used one half piece of metallic cardstock to make the cover. One piece costs $0.38 so half is $0.19. We only used one sheet of paper to make the inside pages as you cut it in half and print on both sides. Cost of one sheet of metallic paper was $0.28. We bought the ribbon from the dollar store and we used only 2 rolls total for 50 invites.
I'm not even sure of the name of the printshop we used. My FI took them to a place near his work. There should be someone who can do them for you. It wasn't very expensive and they printed, cut and folded them for us. We did use a corner cutter on them, which I borrowed from my sister.
My last piece of advice would be that if I were to do it again though I wouldn't use the ribbon because it ended up being too thick and we had to put extra postage on them. So I would just use staples and then you would only need one stamp to send them out.
If you have any further questions feel free to ask!
I attached my template as I know templates sure helped me when I was making mine.