If you’re on a tight budget, the least expensive material you can buy for DIY closet shelves is chipboard, a.k.a. particle board. This inexpensive material is made from a pulp of sawdust, resin, and glue that’s pressed together under high temperature and pressure. As you can imagine, it’s not very sturdy and might buckle under your blue jean collection, so you should only use it if you’re storing very light items. 

Costs depend on material type, size, and additional features like lighting or sliding doors.

Yes, adding a built-in or custom closet generally increases your home's value and makes it more attractive to potential buyers. A well-designed closet adds utility, organization, and a touch of luxury, which are appealing selling points. Most homeowners see a return on investment (ROI) of 50% to 60%; for example, a custom closet can add about $1,000 to your home's value on average. The specific ROI depends on the type, with custom walk-in closets typically providing more value than reach-in closets. However, to maximize value, ensure the closet doesn't significantly detract from the room's usable square footage. Converting an entire room into a closet can actually lower your home's value. Similarly, using overly lavish materials may not recoup their cost. A good strategy is to add a closet that takes square footage from a non-living area, such as a garage, to create a mudroom closet.

You can design your own closet, but it’s usually better to hire a professional to do the work for you. Not only will you get years of design experience to guide you toward the right layout and material choices, but you’ll also only pay slightly more hiring a professional than you would creating your own plans and hiring a carpenter. A high-quality closet designer can provide insight into how to lay out your closet, and they may be able to find you a good deal on the carpentry or complete the work using an affordable, in-house team.