90 dodge 4x4 leaky pump
 

i bought a 1990 4x4 with roughly 400,000 mi or that's what it shows. i paid 2200 for it. i know it might be to high for some or average for others, i'm not looking for a restoration or show truck, i just need a beater truck to drive around as i do not want to put a lot of miles on my other new truck.
that been said i want to get it road worthy so i do not get stranded somewhere as i travel a lot like 600 0r 700 miles each weekend up and down cali and oregon. i wanted a dodge diesel auto 4x4 for quite some time and with my very limited budget this is what i could afford.
my question is how much on average does it cost to repair a leaky injection pump, the guy said it needed o rings.
like i said i just need truck to get around so i dont care for the exterior

thanks to all if you read this