I have a niche website on Australian Standard 4024.1 Safety of Machinery (www.machine-safety-australia.com.au) I am looking to offer banner advertisement and my target advertises are the multi national machine safety suppliers (companies like Pilz, Allen Bradley, Siemens). A sale for an machine safety system can range from $1000 up to $100k+ I not sure what I should set my Cost per Thousand adverting cost at but was thinking because this is such a niche audience making it $100 per thousand. Does this sound alright or is it too high or too low.