Puzzling Over Prices

This is a thought puzzle that presents an interesting paradox. Solving it will require some divergent thinking on your part. Mr. Puh Z. Elle went into Sandy's Specialty Shop one day to make a purchase. Read their conversation below and then try to answer the question that follows. Sandy shop Good morning, Mr. Elle. "Good morning, Sandy. I'm looking to buy some of these. How much does one cost?" "One? That would be 50 cents." All right, what if I buy 12?" Twelve would be one dollar, Mr. Elle. "That sounds good. I would like 312." One dollar and 50 cents, please." There you go. Thank you, Sandy. "You too, Mr. Elle." The above story makes perfect sense if you can figure out what Mr. Elle bought. When you do this, it will explain the apparent price discrepancies. What did Mr. Elle buy?