How many operations per second, or perhaps more precisely FLOPS can I buy for £1, or if you prefer $1?
In comparison can the price and the difficulty be used to work this out for the BTC nework? I suspect not but I also suspect estimates to have been made. I think the number would be need to be reduced by some proportion to compensate for the way that the BTC cloud contains hardware designed only for mining BTC.
Is there a chart showing the price history for thease idearly together?
FLOPS performance is kinda meaningless in the Bitcoin network, since it's just doing bitwise and logical operations on integers. Whatever estimates are there assume too much, simply because every architecture is different in how FLOPS performance translates to hashing performance. (See NVidia vs. ATI)