How to approach Pricing questions in PM interviews

For new products: Pricing is amount that the customer is willing to pay. 

For existing products: Its competitor's price + accessories or customizations. Its called as competitive pricing. 

For new and existing products, you can use cost based pricing. 

Best way to find the price: Vary it over the period of time and based on volume. 

If you can't price the product then you can take customer survey or use some data to come up with expectations. 

For pricing questions, approach it as:

1. Find out cost price and mark it as such. 

2. Look for competitive price and mark it up or down based on it. Make sure to mark it above cost price. 

3. Evaluate supply and demand over the period of time and come up with ideal pricing.