With the rust, all the parts it needs, and extensive cleanup, I think you can find a better deal.
There are a lot of grills that come available periodically that are kept clean, indoors, and in working order for the same $$ or free...you just have to be on the hunt when they're offered.
If you can get it for free and your ambitious it might be a good deal for you but IMO you'd be doing the guy a favor just hauling it off so he don't have to pay to throw it away.