On July 18, 2010 ArtForz started mining bitcoin with GPU, reducing drastically the reward for the rest of the miners. The result was pretty interesting: instead of putting them out of business, the price jumped 10x to fully compensate the new difficulty. ofnumbers.com/2014/04/20/how…
The subjective theory of value states that the value of a good is determined by the importance an acting individual places on it. ArtForz was not selling, so he restricted the offer forcing buyers to reconsider the subjective value of bitcoin and buy at CPU miners price.