1) MDF versus wood. For trim moldings, baseboards, crown, casing, etc...solid wood is authentic and if you have an historic home and need to maintain history, use wood. Using MDF does not detract from the appearance or performance. The cost is significantly lower and the longevity - when primed and painted - is the same. Made without formaldehyde, there is no longer any off-gassing.
2) Plywood versus solid wood. The durability of plywood is well-known. Using it on floors, for built-ins (edge-banding required for a finished edge), and doors.
3) Salvage yards versus new. Builder's supply yards, Habitat for Humanity resale stores, and those in your local area, can be a great resource for bathroom vanities, flooring, doors, mantles and more. You can often find older pieces with lots of architectural detail that simply need refinishing.
4) Spray versus sandblasting glass. For cabinet doors, glass insets in doors, sidelights, etc...purchasing sandblasted glass for its obscurity is costly. Try Krylon's Frosted Glass Finish for a highly cost-effective alternative. Window film is the next option!
5) Wood versus granite counter top. Granite can cost up to $50 per square foot and is often not affordable. Butcher block and other solid species are significantly less expensive and provide a warm, custom finish.
6) Laminate versus solid surface counter. The look of granite without the cost is easily found with laminate counters. Many manufacturers offer laminate - Wilsonart and Formica among them - and the properties of the new laminate far exceed the previous generations of the materials. With a tremendous variety in color, texture and edges, you can find the style and the budget level that suits your project.
7) Concrete versus stone.When paving your exterior spaces, consider a concrete product instead of natural stone. The look is slightly different but the resulting durability and competitive cost are well worth the switch!