When creating an Estimate, it would be really helpful to add sections with sub totals.
Our Estimates are often presented based on rooms/areas. Each area has a number of items contained within it. Our clients want to be able to see their estimates presented in 'sections'.

1) Perhaps introduce 'section header rows'. Which are simply text labels to better present/group items on an estimate.
2) Add sub totals for every section, with the option to display a cost summary at the bottom, listing each section total and a grand total.