I am in the "price will go up camp". Right now there are a ton of miners mining. They need to sell their coins to pay for electricity. They are constantly dumping so that makes the price so low. If many miners went off line, the left over pools would be getting a lot more coins for the same amount of electricity. They wouldn't need to sell so many. They could hold and watch the price shoot up. After it was high, they could then sell a few and have lots of money for electricity.
I don't think that the miners are making up that much of a percentage of the total supply of bitcoin that is for sale. I think that some miners are mining to buy bitcoin at a discount and do not wish to sell immediately
I think it really depends on the miner. Maybe they can afford to pay electricity without selling coins. Maybe some also sell the coins to pay for electricity. Either way, they can only profit if the electricity price is low. There is no point in mining if you can't profit. Unless of course if you only mine to learn how stuff works.