Hiring a closet company to outfit a walk-in can easily run $5,000 to $10,000. But with clever planning, you can knock $1,000 to $3,000 off the job. For instance, most paint-grade wood or MDF systems consist of floor-to-ceiling modules with shelves, racks, cubbies, or drawers. Two-foot-wide modules provide the greatest variety of storage configurations, but if you go with 3-footers, you'll get away with one less compartment overall. This cuts your costs, but not your storage capacity, says Mike Carson, president of Closet Works, a custom shop in Elmhurst, Illinois. If you install your own system from a kit, you can save another $1,000 to $2,000. The trick is to work with a web-based dealer with high-quality materials and good customer service. Designers at easyclosets.com, for example, will create a plan for you based on your closet's measurements and your specific storage needs.