WADR, you may be comparing apples to oranges, even if the "numbers" appear close.
The J is a boat mean to sail with creature comforts added.
The Sabre is a cruiser that "can" race
The $$ in a J is spent on the hull
and sailing features.
The $$ on a Sabre is spent on the fit and finish down below.
I'd carefully check the difference in sailing gear
(blocks, winches, travelers, etc.) carefully and see for yourself.
You might also want to do what I call "The Dipstick Check": how easy is it to access & service
and other components on each boat.
Your boat, your choice.