Flew the JED-DXB leg of this back in the summer (whole trip was DXB-RUH-JED-DXB on SAA and EK) and as with other EK KSA flights, experienced massive, horrible delays.
Some equipment problem meant we were delayed upwards of 5 hours, with little information. I'm Skywards Gold, so was able to use the lounge - but that's no use when the ground staff won't check you in.
I understand this is fairly commonplace for these EK flights - certainly the majority of Dubaians who've used the route that I've spoken to have experienced delays ex-JED.
Even in the summer flight was fairly full, so I'm not surprised at the high fare. Plane was new, though (believe it was 777 300ER but not sure) and ice-equipped, etc.
YMMV, but from my experience I would suggest looking at other routes.