What price should I expect to pay for such stickers?
The answer would depend on what kind of sticker you want and the volumes you intend to purchase. I assume you are looking for Near Field Communication (NFC) transponders embedded in a label or a small sticker. NFC is a type of short-range RFID technology that can be used with many cell phones. A sticker in very small volumes (say, six pieces) costs roughly $1 each. Small packets can be purchased on Amazon.com. The price goes down as the volume goes up. In volumes of a million units or more, you might pay only $0.20 or $0.25 apiece.
—Mark Roberti, Founder and Editor, RFID Journal