It's tough to assign a value to Garoppolo. Fans almost always overestimate a player's trade value. For example, no one would've predicted that trading Jaime Collins mid-season would've netted us a 4th-round pick, they would've expected it to be much higher than that.
There's no way we get the #1 overall pick for him. I think even the #12 overall pick is unrealistic. I think perhaps the Browns' second round pick, and maybe another 2nd next year, is fair -- something along the lines of what the Chiefs gave up for Alex Smith.
The Vikings trade for Bradford is hard to compare to, because the Vikes had no leverage whatsoever, they basically had to find a quarterback last-second. It was a desperation move. That's different from, say, the Browns, who can say, "well, if your asking price is unrealistic, we'll just turn around and draft one of those players available."
It's not just a matter of saying "Garoppolo is more polished than Watson/Trib/etc". It's apples and oranges, because when you sign those guys you're getting them on (essentially) a 5-year contract -- four very cheap rookie years, and then a reasonable 5th-year-option. Garoppolo will require a massive extension, and then hurts his trade value and the leverage that the Pats have.
This is also a guy with only 94 pass attempts on his career. Yes, he's been successful, but the sample size is incredible small and it sort of discounts how well he's played. I think by and large he's an unknown commodity.
