Looking at Spotrac Contracts, there aren't too many comparisons for Bradley by age and years of team control:
Logan Webb is probably the closest I saw, He signed an extension before his age 27 season that bought out his last 2 years of Arb and his first 3 years of FA, 5 years/$90 MM and he's a FA before his age 32 season
Brandon Pfaadt signed an extension before his age 27 season that bought out his last year of pre-arb, all 3 years of Arb, and 1st year of FA, 5 year/$45 MM guaranteed contract, with a team option of $21 MM, with a $1 MM buyout, with a possible mutual option of $21MM - 7 years/$90 MM total contract if options are picked up and he's a FA again before his age 34 season.
Tanner Bibee signed an extension before his age 26 season that bought out his last year of pre-arb, all 3 years of Arb, and his 1st year of FA - 5 years/$48 MM with a $1MM buyout of a team option for his 2nd year of FA. If the option is picked up the contract becomes 6 years/$68 MM and he's a FA again before his age 32 season.
There are others that have contracts that bought out more pre-arb, were International signings, or were just too long ago, but these 3 give a pretty good idea what a Bradley extension would look like.