I was doing the same thing, that's why I built the calculator. It has been posted on my website for almost 2 years, we use it on every removal bid we give and it works great for us.
I've discovered that other tree compainies in the area are also basing their prices off of my calculator, which is cool. If I could get every hack to raise their prices, we could put them out of business.
Another cool thing, my google pagerank has gone from 14 or so to page 1 in two years, and I haven't paid for any search engine optimization.
It needs to have a damage feature so you can input the condition of the tree. Maybe a tree shape too. Like tall straight pole or branchy porcupine.
I just used it on 2 trees and one came in about $100 lower and one came in about $100 higher.
No one here can do that. The only people who can are local to you. You can call them for a quote. Oaks are best trimmed in the winter, and after seeing lots of regrettable hack jobs done by the cheap guys, I'd strongly suggest calling someone who employs an actual ISA certified arborist.