The design of bitcoin and the increase in difficulty make centralization of mining facilities inevitable. We are already seeing this happen, as difficulty goes up and price does not adequately correlate , fewer and fewer people can afford to run mining farms, as this trend continues the transaction processing power of the network becomes increasingly consolidated,  which increases the likelihood of a 51% attack and also eliminates one of the primary functions/features of btc, the decentralization of the system.

How much do you think bitcoin will be worth when there are less than 5 facilities left in the world with electrical rates low enough to run machines? I say 0.