There are three basic types of room humidifiers, each with their pluses and minuses:
1. Cool Mist--Wicking: Perhaps the simplest type of humidifier, it uses a honeycomb wick that absorbs moisture from a tank and then uses a fan the blow moisture from the top of the wick into the room.
Pros: Usually cheap, hard to break as the only moving part is the fan, reasonably quiet, low power consumption, safe
Cons: Hard to regulate moisture, wicks wear out quickly and can be expensive to replace, if your wick is allowed to dry completely it will need to be replace, can be a pain to clean (but they all are)
2. Cool Mist--Ultrasonic-- uses a rapidly vibrating element to turn water into mist and then blow it into the room
Pros: Usually pricier, no wicks to replace, fairly quiet, easier to regulate moisture into room, safe
Cons: Slightly higher energy consumption, more moving parts (but not many more), probably hardest to keep clean
3. Warm Mist-- heats water to produce mist
Pros: Same pros as ultrasonic, warm mist may be better for people (but no better for instruments), easier than most to clean
Cons: Highest energy consumption, most moving parts, some risk as it's hot, often pricier
I've used room humidifiers for nearly 30 years now and have never had one that leaks. I don't think I've ever gotten more than 3-4 years out of a room humidifier before it needed to be replace. I used to use wick humidifiers because they were cheap, easy, and quiet; however, I eventually go tired of replacing wicks and started using ultrasonics. The model I've been using (I've had two now) works well, has a good-sized reservoir, is quiet, and has done a great job of keeping my music room at the proper humidity. It does need regular cleaning, however-- it vaporizes the water, but leaves whatever random gook was in the water inside the humidifier.
If you go super-cheap, you may get poorly made product. There is nothing about a humidifier that should make it noisy or should make it leak, unless it's just poorly made. I would expect to pay around $60-100 for a reliable ultrasonic, perhaps $40-60 for a wick humidifier.