Depends on hauling time for a truck and excavator, minimum hauling cost is 300 each way here (Canadian). A third of an acre should only take a few hours but you have to make sure you have everything ready - time is money for these guys.Should be more than 2000-2500, less if the guy knows what he's doing. If you have to remove material then that could add to it, if you want it set aside and landscaped that'll add to it as well. Cash pricing is usually best and you want someone with a tilt bucket for nice finish work.
I'd use a minimum 10 ton machine, a 20 ton would make quick work of it and sometimes the smaller machines take a lot longer to remove material, cast to another area etc. The key is an experienced pond builder.
Cheers.
