If there's anything widely known about photography and the equipment, it's how expensive it can be! If you are specializing in certain types of photography (eg: insects) it can definitely be worth it. Here's a tip I've learned if you'd like to dabble in macro photography but don't have a macro lens: If you place any detachable lens backwards onto your camera and hold it there, you can still take pictures and get macro effects! To zoom in and out, you must move the camera closer or further away. I took this one using my 70-300mm telephoto lens backwards.
*note - you have to get really close to the subject and be really still! Let me know if you try it and how it worked!