I think there may have been a little confusion. They don't make a rebuild kit for those but we do have the orings that seal the pump sections together. If your pump is just leaking at the seams then you can probably fix it. If it is weak then probably needs replaced. If it does not pump at all it may just be a sheared keyway... Assuming you have checked the screen, oil, filter, etc
There a several different brand pumps going around out there. Some are much better than others. I don't know what BFP sells but just be aware that there may be a difference. $279 sounds pretty cheap for an OEM quality pump.