I haver never heard of a hipostrib variation in the Citori line.
Weight of the weapon.
Sports has to do with athletics and sporting is a form of advertisement.
One of the best references is "Browning Sporting Arms of Distinction 1903-1992" by Matt Eastman.
The 'A' sporting events are a higher class than the 'B' sporting events. Sporting is a lot more competitive and there are more skilled competitors in the 'A'
Built to the same specs. Labor is cheaper in Japan.
The roll marks
Stock and sights.
wood, finish, stock dimensions
Stock dimensions and sights
You have answered your own question.
On a sweet sixteen model,the difference is 175 dollars between the two.
If we are talking about a Browning Citori model 525 sporting shotgun,then the value will be between 695-1,400 dollars based on your shotgun having between 60%-90% of its original finish remaining,and a good set of bores.