A few weeks ago I went to the Women's International Show and bought the Konad C-3 nail stamping kit for $25. It comes with everyone in the picture below and basically all you do is paint over the image on the plate that you want, scrap the excess paint off, and then stamp it on your nail. All of the polish dries within 30 seconds so you have to move fast, but there's no down time waiting for it to dry once it's on your nail. Even though it's a $25 cost up front, I think it's worth it because nail art typically costs around $3 each time at the nail salon.
If you visit the Konad website you can pick between a TON of different products and image plates. You can also buy different color polishes for $6-7 each. Just email the company (firstname.lastname@example.org) and they can place an order for you!