A YMCKO ribbon cartridge costs from $70 to $90 USD, and produces 200 cards. Monochrome ribbon cartridges are cheaper, and go further. Black prints 1000 cards, and costs about $30 USD. Red, Green and Blue monochrome ribbons go for approximately $40 each, and also cover 1000 cards. Gold and silver are more expensive, $95 USD, but also cover 1000 cards. White ribbon cartridges cost $45 USD, and cover 850 cards per ribbon.
Cards vary in price depending both on their composition and their features. 500 standard PVC cards, 30 mil thick, are found online for $77 to $102 USD. 500 composite PVC cards go for $96 to $120 USD online. PVC cards with mag strips can be found for $76 to $102 USD, and composite mag strip cards cost $122 to $156 USD. Cards with smart encoding are also available, for correspondingly higher prices. Zebra also produces custom designed PVC card stock with individualized security features based on a customer's requirements - also at correspondingly higher cost per card.
Some office supply stores rent card printers, and if you are only intending a one time use, rental is probably your best choice. You do, however, still need to buy all the supplies. However, if you need cards for an annual event, or one extending over several days, buying the printer can become a more attractive option than renting it. You could also consider sharing it with other organizations to spread the cost. And after all, once you have the printer, you may find more than one use for making secure ID cards.