I just looked up one of my STRs and - although I didn't sign up for an account - everything from pictures to numbers were all wrong and a year behind......?

I  used Home Depot's Web site to select the doors I wanted and also used the Homewyse website to get a second set of numbers, and they came both pretty close to each other at $1800 products and $1300 labor.I then contact Home Depot to get a person on site to inspect and take measurements, and a couple days later I get an estimate with two sections: Customer Pickup #1 for $2695, and Installation #1 with $0 total.

If you are lucky you can find old pictures on MLS or somewhere on the internet.

Your smaller doors, you will get a more transient customer base. 

@Mark BergeGo to the old boiler and take a picture of the old system and the plate on the boiler itself.

Must have references and pictures. 

Or you work for a wealthy customer who knows the deal and checks up on you. 

@Connor Mohs you're assumption picture might be accurate as high as 10% of the time, possibly.

A few of my wife's pictures taken on 9/5 showed cracks on the cement floors (obvious that I know I didn't notice them when we first saw the house on 8/15), a ~8" chunk of cement missing from the 6" thick foundation pads on which the oil burning furnace sits, with the HVAC 8" inlet metal collar on it rusting already. 

The house from the pictures seems to be in pretty good shape.