Scratch Card Script

I need a very small and simple scratch card type script. A visitor must be able to visit the website, scratch the card and see if he has won a prize. Visitors are only allowed to scartch once a day. Admin must be able to add prizes, with download links if the visitor won a prize, he can download it immediately. The script must add a random prize everytime a visitor visits and scratch the card. I am looking to pay around $30 for this script.