If budget doesn't allow you to create your dream kitchen in one shot, don't compromise. Do it in phases.
Where to invest now:
Layout: This is the time to open the floor plan, add the island, and rearrange the flow.
Infrastructure: Get the framing, subfloor, windows, plumbing, and electrical right or all those new finishes and appliances won't perform as expected.
Cabinets: Go for quality construction, premium glides and hinges, and as many cabinets as you can afford.
Countertops: Conventional wisdom may say to phase-in upscale countertops, but demoing the old and installing new can damage your cabinets and plumbing.
What you can wait for later:
New appliances: Unless you're changing their size or configuration, your old range and fridge will work just fine until you get your next tax return.
Pricey light fixtures: Throw in cheap placeholders while you've got the electrician on hand. You can easily replace lights yourself once the wiring's complete.
Splurge-worthy faucet: You can get a decent one for less than $75 that'll tide you over for months or even years. Just make sure the drill-outs in your countertop match the configuration
of your future faucet.
Backsplash: Paint the walls above your counter with a scrubbable semigloss to protect them while you save up for that glass mosaic. Holding off also gives new cabinets time to settle, thus preventing grout and caulk problems at the seam where the backsplash meets the counter.