Jumping to 300 from 256 & 233 is tougher than you seem to think it is. I'll try to illustrate in terms of current data.
Ben threw for 300 yards only 7 times in 73 regular season starts. In the playoffs he is 1 for 9 throwing 300. So, fair odds on him throwing for 300 in the Super Bowl is over 9 to 1.
Kurt threw for 300 yards 18 times out of 47 regular season games with the Cards. In the playoffs he's 0 for 3 throwing 300 with the Cards. So, fair odds on Kurt throwing 300 in the Super Bowl has to be at least 3 to 1, considering the defense he's going against.
So, true odds for the pair is probably about 2 1/2 to 1. Your bet is reasonable, if you feel you've got some type of handicapping edge, but I wouldn't be doing backflips or anything about it with respect to the other two individual passing props you indicate above.
As far as their individual 233 & 256 o/u, I'd take Ben with the under 233 and Kurt with the over 256. Ben has only thrown for over 233 in 21 of his 73 regular season starts and 3 of 9 in the playoffs. Kurt has thrown over 256 in 27 of his 47 games with the Cards and 2 of 3 in the playoffs. Kurt was even better with the Rams, if you want to dig into those stats, but I stuck with his Cardinal stats only because it's more relevant to his current teammates, situations & coaches.
Ben threw for 300 yards only 7 times in 73 regular season starts. In the playoffs he is 1 for 9 throwing 300. So, fair odds on him throwing for 300 in the Super Bowl is over 9 to 1.
Kurt threw for 300 yards 18 times out of 47 regular season games with the Cards. In the playoffs he's 0 for 3 throwing 300 with the Cards. So, fair odds on Kurt throwing 300 in the Super Bowl has to be at least 3 to 1, considering the defense he's going against.
So, true odds for the pair is probably about 2 1/2 to 1. Your bet is reasonable, if you feel you've got some type of handicapping edge, but I wouldn't be doing backflips or anything about it with respect to the other two individual passing props you indicate above.
As far as their individual 233 & 256 o/u, I'd take Ben with the under 233 and Kurt with the over 256. Ben has only thrown for over 233 in 21 of his 73 regular season starts and 3 of 9 in the playoffs. Kurt has thrown over 256 in 27 of his 47 games with the Cards and 2 of 3 in the playoffs. Kurt was even better with the Rams, if you want to dig into those stats, but I stuck with his Cardinal stats only because it's more relevant to his current teammates, situations & coaches.