People often assume that getting a gorgeous kitchen like the ones they see in design magazines would require draining their bank account. And often, they’re right: Building a custom kitchen with upscale materials and finishes can easily run into six figures. What they might not realize is that there are cost-saving alternatives that can deliver a high-end look for a fraction of the price. One of the most popular, employed by a number of architects and designers, is building a kitchen with Ikea cabinets and then covering those cabinets with custom doors, drawer fronts and panels from companies like Reform, Semihandmade and Kokeena. “Ikea makes a great box,” said John McDonald, the founder and chief executive of Semihandmade, a company based in Monrovia, Calif. And inside its Sektion cabinets, he added, Ikea “uses the best hardware you can get.” Those hinges, drawer slides and other pieces, he said, are from Blum — the same brand of hardware that many custom cabinetmakers use, although Ikea’s products are far more reasonably priced. Nathan Cuttle, an interior designer who founded the New York-based Studio Nato, has built numerous kitchens with Ikea cabinets and custom doors from R...