I would be very careful of smelting any ore, much of it can kill you, the guy selling it may not have any idea what he is selling, and may just send you a bag full of arsenic ore to poison yourself with.
If it did contain values and he knew how to get them out and make a profit he would not be selling this ore on ebay a pound at a time, he would be making the money from processing the ore, or selling it by the ton to a smelter, or paying a smelter to work for him.
Besides how many tons are you going to buy, and how many grams of values does the ore contain? how are you going to process grind, roast, froth float or leach and concentrate of these tons of ore before you get to the point of being able to smelt a crucible of this ore?
Tell him to send you a free sample, then send this sample to an assay lab, then determine how many tons of this ore you will need to get a gram of gold, then calculate how much it will cost to process it, what process would be best, how much your cost will be for all of the mining equipment needed, and chemical and waste treatment, and see if you find you can make a few dollars then buy a few trainloads of his ore, and see if you can make all of your plans work.
After all of that you may find out it is just another scam or get rich quick scheme.
I have seen on eBay before people selling ore that were selling slag from smelting processes of old mining operations claiming the ole times left gold in the slag ore, why would an amateur buy this trash off of eBay thinking they could re-smelt it at a profit, when professional miners with much better knowledge and equipment threw this material out as waste, after they collected the gold?