Would it be worth it to fix a small gap with braces?

Probably: If the only problem is a small gap, orthodontics can fix it quite rapidly. I think the time and cost of such a short course of orthodontics better than filling the gap with restorative materials, which make the teeth look (and be) wider, and will likely have to redone several times as color and other changes make it necessary. Yes, it is worth it!

Depends: The answer all depends upon how you feel about your space! many people love their space. Check out madonna, lauren hutton, david letterman. Closing a space with braces can take a significant amount of time. Check with your dentist.

If ti bothers you...: Yes! orthodontic treatment is considered for several reasons. Primarily for bite and periodontal issues associated with malocclusion. A gap between back teeth leads to food impaction and breakdown of the gums in that area. Esthetics is another big reason people pursue orthodontic treatment. If the "gap" bothers you, if it affects your self esteem, then get it fixed.

Values: That is a value judgement that only you can make for yourself after weighing the benefits (esthetics) versus the costs (professional fees, wearing braces). If you dislike the gap, then seeking an opinion with an orthodontic specialist will help you make the best informed decision possible for yourself.

Subjective: It depends if its worth it to you. For some people the answer will be yes and others no. No one can really answer this for you but yourself.

Decisions, decisions: This is usually a value judgment with no right or wrong answer. If only for esthetics, it's up to you. If food collects, more important to close space. If ortho, also need to consider maintaining teeth with retainer? Also dependent upon shape and contours of teeth. Sometimes bonded fillings are best alternative-simple, quick, inexpensive, and if done well imperceptible and can last for 10 yrs+.

Depends: A small gap, especially between top front teeth, is usually not a functional concern, but it is an esthetic concern. If it bothers you, have it fixed. Consult w both orthodontist and cosmetic dentist. Often, working together, the result will be superior to fixing it with tooth movement or with restorations alone. Consult with both, you'll be glad you did.