I'm involved in the second of two major projects in 3 years. In general, the less expensive materials are quite adequate -- often not the cheapest, as in flooring, but a step or two up. Get several quotes and opinions on floors, cabinets, -- anything you will contract. Not just for a good picture of prices but for what they tell you about materials available. Cabinets vary greatly in price and are not cheap; both times we got the best deal from a local cabinet maker, over the big box stores (Home Depot, etc.) Stay with easy maintenance floors and counter tops. Word of mouth or the bulletin board at the local hardware store are good sources.
Stay with easy maintenance finishes for countertops and floors. Be sure the kitchen counters have the backsplash continuous with the countertop, or you have a pain in the neck daily cleaning chore. We used some pretty black floor tiles for the first kitchen counter -- it was awful to try to keep it neat looking. The floor tiles were on sale and a good idea except for the shiny surface. I would never get wood floors; even with modern finishes they are far from easy to maintain. Not ho0w I want to spend my days, and I grew up on oak floors. A local carpet outlet turned out to be a good source for both carpets and linoleum/vinyl flooring. Ceramic tile is very costly and we never found anyone that installed it decently; my son even worked in this business for a while and found it it is very tricky and you really need to have a talent for it. No ceramic tile the second time around.
Are you doing the outside? You don't want concrete siding -- takes an incredible amount of caulking and still is not bugproof -- vinyl is the most economical way to get a decent finish -- again, don't get the cheapest but a step or two up is fine. Roof? Metal, hands down. Windows and doors? Lowe's or Home Depot. Got the bathroom vanity/cabinet at Home Depot the first time, from the cabinet builder the second time. On kitchen drawers, watch out for inexpensive drawer hardware, it will wear out fast. At least make sure you can replace it if needed.
Closeouts are your friend. Our local dollar store carries closeout flooring, very reasonable, believe it or not.