Actually, no. Actually, two sides of the same coin. Most people go into denial when they find out that they have just spent a lot of money on something that really is not all that great.
Overpriced and overrated are two different ways of saying something has a bad quality/price ratio. But if you say overpriced the emphasis is on the price being too high, whereas overrated imo implies that there's something wrong with the quality. Which is not the case.