Having a dog bed is not a luxury. It's a basic necessity. Most dog trainers will tell you that allowing your dog to sleep on the bed with you, confuses them on who the pack leader or boss is. If you agree with this then you probably already own dog bedding and either have it in your room on the floor or in the front room. However for all the other dog owners still sharing their beds with the dog here are some tips on why a dog bed is a good idea.
For older dogs getting up and down from a bed maybe hard on their joints and muscles and they can benefit from having orthopedic dog beds designed for old bones. Some even find that a heated dog bed helps relax the tight muscles of older dogs or ones with joint problems.
Some designer dog beds can be made to fit your rooms decor or even match a child's room if that is where to dog sleeps. If you have a small dog that tends to be a little scared having small dog beds tucked away in the corner of the bedroom or closet can give them a safe feeling without getting kicked of the bed at night. My Lhasa Apso use to sleep under the covers at night but would tend to get in the way of my sleep, after buying a small dog bed for her and putting it between the headboard and wall she and I both slept better.
Dog beds can be very expensive so if cost is a concern search online for discounted or cheap dog beds and you can still find a good choice.