I agree that getting an old machine to play with would be easier/cheaper. But some of us just can't help ourselves. I'm working on a PI detector. We don't have any gold or silver in KS. We don't have many old coins here. So I'm looking for a meteorite. I want to build small, med, large coils. I just spent $40 on a signal generator to test coils, I could have bought an old MD for that. Now if I could just get back to it, I keep having other chores like cutting some more firewood before the weather gets too cold.
If you want to find out how deep those waters are, go to Geotech and Findmall forums