I have heard good things, but have never owned one. I do know that there are some pieces that break easily if not used carefully - I believe handles were the main issue if I remember correctly.
To be honest, I would need some kind of assurance in regards to whether it works and how long it has been used. I would take it completely apart and look carefully at all parts. I would also require that they show me it works on a functioning aquarium. Lastly, I would not pay more than $18 - unless they are including media or something else. There is risk involved when buying used, especially when purchasing an off brand filter.
Well, just saw the above. He may be right, I would definitely think twice.
