Cost of a lawn on a new build

Just wondering if anybody had any recent history with this.

Moved into my house in April and am going hoping to get lawns done. As a moving present my family have promised to pay for all the digger work needed to level off site. So I have sprayed the site with Roundup and in a couple of weeks my digger man will be coming into level off the site.

So basically I am wondering what it would cost to get a guy to take on the job from that point? Im by no means an expert so while I could make a decent fist of it I'd prefer to get a lad who knows what he's at. The lawn takes up roughly one third of an acre.

Thanks in advance for any expert out there who knows his stuff.