Goff, Wentz, and all the others should be a cautionary tale against paying market rate to average QBs, but alas, this is football, not rocket science.
Go three-deep with read-option QBs on rookie deals and run an offense like Baltimore's on the cheap while stocking up on talent around them. Rotate them in and out like RBs to create mismatches if you have to.
When the market creates a bubble, you find hidden opportunities elsewhere. I swear sports is the only place where otherwise reasonable people think "Buy High, Sell Low" is a winning strategy.