Simple question, not so simple to answer but we will give you some ideas. Closets come in all sizes and shapes. They can be outfitted with many different types of materials and everyone has an idea as to how they want it to work.
Your Existing old closet may cost you simply because it is under utilized and poorly laid out. This cost you time every morning as it is hard to find things you know are in there. Clothes become crushed and wrinkled and need to be touched up with and iron or steamer before you can wear them. Space may not be used or can be blocked due to a configuration that just won’t work.
Materials today range from plank and poles, Ventilated “wire shelving”, adjustable shelving or elaborate solid shelf systems complete with drawers and pull-outs. Each one of these has a price point for each type of closet shape. A reach-in, generally 2 feet in depth is common with walk-in closets going from small to large to very large and can hold a center island. A layout can be basic, medium or elaborate depending upon how important each closet is to its owner.
A factor to keep in mind is Labor. Who is going to do the work? Doing it yourself or have a handyman or a professional have various levels of service and benefit. Doing it yourself is cheaper but sometimes the work does not get completed as life happens. Hiring a professional has a cost but helps give you ideas for layout of space and ensures the system(s) are installed correctly.
Lets look at the two main categories of shapes.
A Reach-In Closet – 2 foot deep by 5, 6 or 8 foot in width.
Figure about $100 per foot of width for better systems
A Walk-in Closet – ranging in size from a 5 foot by 4’ to an 8’ x12’ or 12’ x 15’
Drawers in the closet are a great way to help you organize and possible get a piece of furniture out of the way in the bedroom. These are like dressers fitting the space. A drawer can add about $100 each by the time you figure the cabinet and system to hold it. There are different types of drawers too from cheap plastic to deluxe wood constructed with soft close drawer slides etc. Example: 5 Drawers equals a starting place of $500.
Wire is weight rated at about 35lbs to 50lbs a running foot.
Adjustable shelving (mounted correctly) is rated at about 100lbs per foot on the system – all shelves combined, weight evenly spread out.
Floor based systems generally solid wood or laminate can hold 100 to 150 but depend upon how it is constructed and also installed.