When determining the budget of a kitchen renovation, the size and condition of the existing kitchen are the first items I look at which will effect the cost of the major ticket items: cabinetry and countertops. Can we reuse the existing boxes or do we need to demolish and replace entirely?
The cabinetry is a huge budget item and the difference between reuse and new can be tens of thousands of dollars. Then determining the countertop and backsplash materials (natural stone vs man made) and the level of appliances (mid to luxury range). Once I understand the client's expectations and the state of the existing kitchen, the rough budget is illuminated fairly quickly.
Appliances: Ask yourself if you really need the luxury brands? Are you a cooking enthusiast or want the brand label for resale. If neither of those describe you, mid-range American brands will perform well. You can also ask the appliance sales rep about purchasing floor models or discontinued models they need to move.
Countertops: Engineered stone slabs can look just as good as natural stone and offer considerable savings and durability. Think outside the box and consider terrazzo slabs or even tiling the countertop (not yesteryear's version with 3/16" groutlines, ick.) Tight grout lines between smooth glazed tile surfaces that extend vertically to become the backsplash.
Backsplash: One of my favorite things is to get creative with tile patterns. You can do so with fairly inexpensive tile. Subway tile and concrete tile are budget friendly materials suitable for backsplashes (but not for countertops) that can infuse a kitchen with a sense of play. Sealed and moisture resistant plaster finishes are an option, especially if you are open to a DIY install. I have seen people skip backsplashes except for behind the range for a cleaner look, as long as they are meticulous about counter wipe downs after each use. If you have existing plain white kitchen backsplash tile, you can apply vinyl decals to update the look with a pattern and skip demo all together.
Cabinets: The best way to save money on a kitchen renovation is to reuse the cabinetry. Either paint existing faces for a fresh look, or have a local cabinet maker remake new faces for the existing boxes in a contemporary style. Gamechanger. Otherwise, I do recommend maple wood boxes if you can't reuse what's there. I know the MDF boxes with thermofoil faces are tempting but they will not withstand the daily wear and tear on a kitchen. The countertops and backsplash will. This will result in regret in a few years time when you find yourself needing to renovate again. Please trust me on this one.
Flooring: I'm all for continuing the wood flooring from the main part of the house into the kitchen for a seamless look and avoiding coordinating (and paying for) different vendors. Engineered hardwood and a new generation of vinyl floors will perform well in a kitchen. Just please have them install the flooring before the cabinet boxes are set. Avoid installing the new flooring after the cabinets are installed and stopping the new flooring at the toe kick.
Cabinetry is a place I wouldn't skimp. If you are going to pull the trigger, do it right and get new cabinets made in quality materials that can withstand daily use. It's also an area to save money. Ask yourself if you really need upper cabinets that can feel boxy and dated. If you can leave some of the walls blank, you can save money and achieve a more open look.
Other decorative items like hardware and lighting won't have an immense impact on the total budget. I recommend getting the items you really love, even if they feel like a splurge compared to everything else. Those details will elevate the overall look and get you to the feel you are ultimately after. Hanging real art in the kitchen will also get you a higher end look (especially if you opted out of installing upper cabinets and have empty wall space to fill). Art can be framed art photography prints and vintage original paintings (look on Ebay and Etsy or local flea markets) to save money. Go as big as possible for a gallery feel.