Answer:
Because it looks like a deal
Step-by-step explanation:
The full price of $510 is equivalent to $17 paid for 30 days. However, the $510 appears to be a huge figure when a customer is asked to pay at once.
The $17 sounds like a good deal. It is a psychological way of making The TVs appear cheaper. The advertisement is creating a perception that customers are getting TVs at a lower price.