I know this is an old post but I thought I'd share what has helped us facilitate quick quoting.
We have utilized the custom fields options in Jobber to add a Grass sqft. option to each property. When we **bleep**/measure we put the measurement info there. The info in the custom field shows up on everything related to that client from that point forward. Let's say 37,000 sqft for this example.
Our mowing line item is setup where each 1 quantity = 1,000 sqft. When we create a quote, we just pop 37 into the quantity (since we can see the custom field of 37,000 sqft on the quote creation page) and we have our price for that property.