To make a transaction, you have to spend a certain amount of gas. This will then be multiplied by the constant cost of the transaction. But gas fluctuates based on demand. If many people want to make a quick transaction, gas will go up as the amount of transactions per block is limited. Avg gas was around 70 gwei yesterday. Currently there's tons of blocks averaging between 1000 - 1500 gwei, which is a lot.