Does the selling becomes difficult if the price for the product you sell is high?

If you have to sell a product with high price , marketing department must create a high value . The consumer should be conVinced that this expensive product is "worth buying" .  Its all about thé " perceived value" of thé product by thé consumer. Marketing should design a unique value proposition for that product . If not , a sales person can not convince thé consumer to pay high prices . The consumer always buys a "perception and a value" not a product . If thé advantage of thé product is being perceived and understood , thé consumers do not reject the product/ brand with high price . 

no i don't think so. It all depends on the product you are selling.

For example, in case of Apple i phone market. U can see a gradual increase in prices of new i phone but people still purchasing that product

Nothing is impossible with good attitude and marketing skills