I think the advantage to eBay would be that used equipment is available. This drastically reduces the price. I don't think you will get a high end multimeter for 100 bucks from supply house. I definitely see where you are coming from hvaclover. Buying something off eBay is.def a little bit of a gamble. I don't know bout you guys though.but I.dont do this job cause I get rich doing it. It's a struggle sometimes to be able to afford some of the tools and if I can find a way to save a buck or two.so I can buy my kids something nice than great.