i STRONGLY rcommend to do NOT waste time and gold with rep gear
the only exclaimation is maybe coba plateau, where you have to grind for 3 levels, there prospector rep gear might be useful
i have leveled 9 chars to max level so i know
Not worth it. At 35 you can buy a full set of green gear that have item level of 37+, rep is required only to buy it not to open the box which is not bound, so you can just ask someone with the rep to buy and trade it to you.
Ofcourse if you have obsessive compulsive disorder (like me), you'll still want to finish all the reps after you hit the cap. For completeness sake.