So, as you can see, it's simple to dig a trench, spool out some wire, backfill, and turn a screwdriver to tighten a few nuts.
The labor on doing this is easy.
What's difficult is sorting out the many details of what you want to end up with. That's why the electrician gets paid a lot. The details of your exact location and needs......
you will need direct burial rated cable, or conduit and wire rated to run in conduit underground. (They use different coating, some rely upon being in touch with cooling dirt, some can sit in the air inside a conduit without melting, some can work either way, etc. all types of coatings for all types of uses, match them up right to what you are doing!)
You need the wire buried at least into the teens of inches deep. Different locations use different versions of the Electrical Code Book, so they might differ a bit. You might need to go deeper in special cases, and you can always go deeper if you want. Many just trench 2 feet to give a little extra cushion?
You need metal or plastic conduit protecting the wire when it leaves the ground and cones up the side of a pole or building. Think everyone uses plastic these days.
Your wire needs to be sized for the load you want to carry, plus it needs to get bigger as the distance increases. Wires carrying electricity heat up. Maybe only a degree or two with a small load, but as the amps increase and/or the wire is longer, it creates more heat. This heat is wasted energy, and reduces the volts you get at the far end. And so this is why we need to size the wires for the correct amp load and distance of the wire.
A 120 service uses 3 wires. Hot, neutral, ground.
A 240 service uses 4 wires. Hot hot, neutral (used with one of the hots to make 120v), and ground.
The 4 wire 240 service is -much- more flexible and offers you a lot more options. As I said below, it would be pretty foolish to go to all this expense and then leave out that one extra wire to save a very few bucks......
If you could tell us what size motors and how many lights and so forth you use at each bin, and the distance between the service pole and the bin site, several could give you a wild guess as to what size wires you would be looking at?
It sounds like you just want an idea of what you are in for, and what it might cost?
Many times electricians have a cheap helper with them to do the rough work - the digging, the unrolling wire, etc. and the licenced electrician just designs the plan of what is needed and does the final screw turning to get the right wires connected proper. It is possible to find an electrician that will do his parts, and let you do the grunt work of digging trenches, unrolling the wire he specifies, etc. now be careful on this - you cant expect him to give up his income either, he needs to get paid for those expensive, decision making parts. But it might help you cut costs if you find a guy willing to let you do the simple parts.
When I put up my machine shed I was running water pipe and draibage tile, and had a trench about right from the power box to the machine shed I put up. The electrician was happy, he didn't have to bring his trencher out, and saved me a lot of money on that part of it..... He was overworked and so he could get paid for the expensive parts, but didn't have to waste time on the flunky work.
Paul