I would never pay a QB in today's market unless they were a bonafide future hall of fame type talent like Burrow or Herbert.
Pick one in the first round, play 4 years with them, pick up the 5th year option, turn and burn if they are good but not great. Build a contending roster around the player and just slot in the next 1st rounder. After enough tries, you should have gotten lucky and gotten one of those top guys or have won a Superbowl with a good starter on a cheap rookie deal.
Why NFL GMs are too afraid to emulate the SanFran model is very confusing to me.