"My thesis work used He3...essentially it does not exist naturally...It comes from the beta decay of tritium. So What I got most likely came from the decay of our tritium stockpiles. It is expensive, $400 for 1 litre at STP. I had to do ~100 of hours of experiments with just 5 litres...

It has potential as a fusion recource, when we develop the tech the price will skyrocket... right now only a _few_ researchers have any use for the stuff, but when it is needed by the 1000's of litres it will be the single most precious commodity by weight than any thing on earth...

I would bet that the worldwide demand for the stuff now is _well_ under a litre a day...10 litres lasted me several years and damn few other researchers would need to use the stuff...I only used it for VERY special reasons... It is pretty much identical to regular helium... except in its mass... and that was important for my work but would not be important for the vast majority of researchers...
In fact it turns out I probably could have used regular He4 but I didnt know that until after I built my experiment.

So what I am getting at is that if we learn to use He3 for fusion it will be worth mining wherever we find it."

The price for a litre of water (if you could buy it) on ISS would be higher than $400. The cost per lb of anything lifted by the Shuttle is around $10,000 (so price would be $20,000+ per liter of water) if you used the cheaper russia launch the cost would be more reasonable but still more than $400 per litre (around $2000 per litre).
Getting anything to the Moon is "about" 5 times more expensive than getting anything to LEO. This means if NASA was your freight company you could expect the cost of shipping anything to the Moon would be around $50,000 per lb. If you used Russian or some other low cost shipper you might get your cost per lb down to around $10,000.
This means that anything you need on the Moon which shipped from Earth costs around 10,000 per lb and is worth at least this amount.
Unless:
1) You lower the launch cost.
2) You get what you need from the Moon and the total cost "of doing this" is less than the shipping costs from Earth.

All righty then, here is a chart:
http://silver.neep.wisc.edu/~neep602/FALL97/LEC19/4slide.html
Using the Median value it looks like there is around .007 parts per million of He3 in lunar regolith. Compare this to Hydrogen which has around 60 parts per million. So in a billion lbs/kg/tons you get 7 lbs/kg/tons of He3 or you get 60,000 lbs/kg/tons of hydrogen. On Earth, which is more valuable 7 lbs He3 or 60,000 lbs of hydrogen? I think the Hydrogen would have the higher price. On the Moon there is no question about it, Hydrogen is worth far more. He3 is pretty useless unless you happen to have one of these yet to be built reactors whereas Hydrogen is very useful- it's fuel for rockets. Hydrogen has many uses plus you are getting around 9000 times more of it.
It would be very difficult to mine He3 at such a low concentration, but let's simplify- it make it easier for the He3 argument. Put two boxes on the Moon one has 7 tons of He3 and the other has 60,000 tons of Hydrogen.
Which box do you want to have?
Hint: in order to ship 1 ton of hydrogen at 10,000 per lb it costs 20 million. If you times this by 60k you get idea of highest "asking" price on the Moon (1.2 trillion). With He3, you of course need to ship back to Earth- and you will need to wait until this reactor is built- right now it's not worth the trip.

Now, I'm not suggesting anyone mine hydrogen from the Moon regolith at this time- we need to find the water at the poles, which probably be easier to mine (more concentrated, better location, etc).
-gb