I'm afraid your idea of "high grade" will most likely have to be, in older times, "fair to midlin grade". There weren't a lot of mines that left high grade ores just laying out for anyone to find. There were sometimes ores that were set aside and forgotten, and ore that fell out onto the ground. There was a lot more cost associated with milling ores back then, so there lower-grade ores can still be quite valuable nowdays.
As for your equipment, I'd look carefully and do lots of research. That unit you mentioned that has a crusher with a sluice, what kind/brand of sluice do they use, and why? Is it better? Or is it just more equipment that they can package in for making more money?
I was thinking the same way some time back. For years I had thought about different ideas in placer mining. Then as I kept hearing horror stories about all the regulations and eco-terrorists, I thought about going hard rock. Signed up with GPEX forum (FANTASTIC group of people!!) and have learned tons. Have met some folks that, for some unknown reason, have taken a liking to me and have offered to help me get started. So, back to the studying. Then, in trying to learn probably more than I should, I stumble across another idea that catches my interest. With this idea, there may not be any competition NOR many customers, but I wouldn't need many customers. So then while planning all that out, I tried to figure a way to handle/dispose/use my waste. That led to yet another idea - the one I'm really trying for!! Will start with the first unexpected idea, as the startup costs are lower. Then will grow into the other - which I expect to take off like a shot! ...But time will tell. So until then, I just keep thinking and studying and planning, plus I keep trying to help out here as much as I can - helps keep my mind active and learning lots of new things.
It's a never-ending process for me. Still want to try my hand at both placer and hard rock some day, but more as a hobby by then, I hope.
