The dirtbikes cost 3*150=$<<3*150=450>>450
The off-road vehicles cost 300*4=$<<300*4=1200>>1200
He had to register 3+4=<<3+4=7>>7 vehicles
That means registration cost 25*7=$<<25*7=175>>175
So the total cost of everything was 450+1200+175=$<<450+1200+175=1825>>1825
#### 1825