May I have a sample of this unit please? I see the minimum order is 300 but what is the price you are asking for? I am very interested in the sample, however also need to know about spare parts in case of replacements (spare sensors etc.) What cost and shipping time, please? Would it be possible to get a sample of 1-5-10 units instead of 300 for the first time just to see the quality? I am very interested in.