Setting limit orders

Say, I wanted to purchase BNB at 500$ and the current price is 550$.. You'll have to continuously watch the price on PCS/CMC until your target is reached. But what if u could stake cake instead for a token like BNB, you keep earning from the pool, until your price (wrt cake) is reached and as soon as it reaches PCS automatically purchases the BNB for you. Similarly, while selling you set up a target price and as soon as it's hit, you receive cake in the pool. This would imply more trades, and hence more burns, driving up the price of the cake.. Also, it would make it easy for the users to purchase their tokens of choice at the price they wish to wrt cake.