If you need a quick view of the profit and margin you can view this directly on the quote/order window, in the titlebar (without needing to open the full Costings window).
The figures are hidden in case your computer screen is customer facing.
You can see the profit (shown after P in pounds) and margin (shown after M, as percent) in the top title bar:
E.g. profit is £1137, and margin of 30%
(To enable this display of profit and margin you need to select it in System Config > Quotations & Pricing > Pricing and tick the box Show the margin at the top of the quotation).