I agree with OP on this. Some vendors are quacks asking the questions about the machines they are selling is just a waste of time. Getting a good guide proves more efficient in the long run. My dad used to say that it is better to look for something original (even if it is expensive) that will give you a long service; as opposed to something cheap that you will end up making a loss with. Always remember that cheap is expensive my friend. Sorry for the wall of text.