about the fuel, try regular diesel and iftex system D. I've found that is yields better results then premium diesel and is cheaper. Also, its a recommended additive.
Regarding the oil - its costs that much if you buy it from them, Next time , buy 6(5+1)L of mobil delvac MX and give it to them. it costs much less outside(cost me 1.2k for 6L) , and is a better oil than the super 1000. Of course , do check if they will accept oils from outside, and if not, ask your dad's sumo mech to have the honors
