Worked examples that show how the calculator thinks. They are illustrations, not a verdict on what you should buy.
Why a salary headline is not a purchase price, how take-home and leftover cash change the answer, and where to run your own numbers.
A payment can look fine as a percent of income and still leave too little after rent, debt, and everyday bills.
Scoring bands and sources are on the methodology page. The calculator is the product — these pages exist so you can see the reasoning before you enter private figures.