hmmm... a thought. if people stopped mining and just bought Bitcoins instead, the demand for Bitcoins would go up causing the exchange rate to go up. So people who no longer mine may still be trying to get people to stop mining for their own profit.

Actually I want to use the bitcoins I bought a while ago to purchase a miner, or at least shares in a miner. Is that the same thing?
Kinda same, but share is higher in risk as in you have to pay for their management fee too...