Not really :) Just buying a new house and wouldn't wanna spend too much on the irrigation system. The only thing is, I don't know what too much is ;)

Then I'd either pump it to the main plot or have some sort of ducting take it there.

But thinking about that, the cost would come to something in the region of one or two thousand if I were to have it done professionally I imagine.

But just having a butt on a still and draining it periodically with an hosepipe, would come to about one or two hundred. Maybe £50 to get a plumber link it to your grey water.

If the OP is trying to set himself up in business he should have said. It's a good idea but not a staple earner.

If he's moving inrto a new house and can afford to hire a small digger, he should consider putting land drain pipes in to take his bath and washing machine water.

But not if he is thinking of going organic. Soap is OK (I think) but detergent is full of phosphates. Even dishwasher soap is a fertiliser. (It's used to make homebrew.)