You don't mention what you are currently using. In any event, if you want to photograph candles, you most certain can with just about any camera. However, as with any camera, there are going to be limitations. For example, if you need a long exposure because you're photographing candles in a very dark area, then you'd want to use an adjustable camera such as a mirrorless or DSLR. Any DSLR or mirrorless camera will be more than good enough to photograph candles, or whatever you choose, in almost any lighting condition you can think of.
You don't state a budget, but you do say you want to keep the kit below $900, and that's fine. Any Canon DSLR like a T series will be a great choice. Most mirrorless cameras like those from Sony or Fujifilm are excellent options, too. However, some mirrorless cameras do not have a viewfinder which is something that you most definitely want to have. So avoid any camera that doesn't have a viewfinder.