The monetary value or bitcoin price is the life of bitcoin, without it bitcoin will be just a computer digit. Price has given bitcoin a value and become a currency. With regards to price inflation and deflation it is controlled or caused by the demands and supply in the market. And another if someone sells a bitcoin in a huge volume lower than the current price then the price will go down. But if someone bids a higher price than the current one and purchase huge volume it will increase bitcoins price. But aside from that the miners difficulty the blockchain rewards the demand and supply must be taken into consideration to understand the price trend.