Here is the problem with your logic ... $3/1000 hits I guarantee you is popup traffic, which is as dirty as TGP traffic, and often not at all targeted.
If you want to throw away your money, I'll set up a $3 weekly subscription button in paypal for you ....
At least you will have the satisfaction that your money is being put to good use (for me!)
Seriously ... CPM needs alot of traffic to make anything worth talking about.
Same deal goes for mainstream brokered traffic as with adult for the most part. If the traffic was valuable, do you really think the brokers would be unloading it at bargain prices?
Food for thought.
FF