for buyers, it's gpumaxcasino.
While I don't have an invite yet, it sure seems to me that many miners (and potential gpumax purchasers) have a rather shortsighted view.
In most any business I've been involved in, the expectation of profitability is more like 36 months, and miners seem to expect profitability in 8 or less.
Pretty unsustainable.
with a 3-5 year outlook on BTC, mining at high variance at a 60% premium (with no capital expenditures, no recurring expense or labor expense) still looks looks pretty attractive.
In the end I would envision that many mining ops will sell their services for immediate profit, while other services will buy those and resell those services. This make actually diminish the risk of anyone purchaser controlling too much network.
In the telecom business, it's
very difficult to
guarantee that 2 ordered circuits are
physically distinct (for true redundancy) because each of the telcos leases excess capacity to each other, based on complicated hedging methods and the spot prices for transport (etc) - in many cases Telco A leases dark fiber to Telco B who leases it to Telco C who
then leases it back to Telco A - at a certain point, it's really hard to know who actually owns the fiber in the ground.
I'm willing to bet that mining gets to be like this to a large degree, and as I think about it right now, that seems like it might add to security rather than detract from it, in the long run, because it will distance the actual miner from the will trying to wield it (making the purchaser's attempts at attacks much more difficult, especially if there are vigilant miners)
I'm just suggesting that this rate of profitability is generally unsustainable long term. It's not clear how long the rate of the exchange rate increase will sustain those kinds of ROIs, nor is it really clear how much future network events (difficulty, reward drops) will affect that ROI. And this is why buyers will pay a premium. 
