What would happen if suppliers charge less than the equilibrium price for your good or service?

Because of both demand curve and supply curve are a correlation between price and quantity, and the equilibrium point is the point which between consumer (buyer) and producer (seller) have the same expectation (reflect on the amount of quantity and price). 

In my opinion, your question that suppliers charge less than the equilibrium could not happen, because equilibrium is an intersection between demand and supply curve. Equilibrium is a result from the buyer and seller transaction. Perhaps you want to ask, what would happen if suppliers cuts their product price?. And the answer is the supply curve will simultaneously move to right. 

Remember, in economics as a buyer the more number of good you want to buy, the cheaper price you want to pay, but as a seller, the more number of good you want to sell, the higher price you want to sell. This happens because its nature.