Thanks, no ground wire, forgot to mention, this is service feeder, no ground wire.600 kcm copper is about $20/foot.
So about $250 per foot for the wire, or a total of maybe $25,000 for the wire.
What are you planing to do for the ground conductor? Will need to be a full sized ground wire in each conduit.
2/0 ground X 300 feet is about $5/foot so another $1500.
4#600 plus ground will take probably a 5 inch PVC conduit so add 500 feet of that. Maybe $20/foot, so $10,000.
Trenching and filling is probably about $100 a foot by the time you get done with it. Maybe $10,000 contracted out.
So close to $50,000 in parts and trenching not counting your labor and markup.
Just my guess.
The savings in wire cost should more than pay for increased conduit size, or even conduit quantity.
4 sets of 500 AL in 3" will be the same ampacity as the three sets of 600 CU. 500 XHHW AL is 2.40/ft. So 24k vs 5k for wire. I know what I would use......