Tricky to say one lump on 80k would be better or worse than another on say 40k, assuming we're talking a few ton difference in asking price.
I'd be happier paying for a 80k engine that's proven to have had all the right TLC, proven to have done the stated miles, than a low miler that might seem a bit too good to be true but doesn't have receipts for oil and belts, and a verified mileage to back it up.
Don't get rushed into it, and try and find somewhere or somebody that's reliable in procuring good lumps with all the paperwork.