If for example you got your 60gh single upgrade right now... ROI in under a week.
Singles cost 200 btc back then and now generate 1 btc per day. ROI is already at 6 months assuming no difficulty increases. But as we all know, there's lots of increases on the way. A single delivered now will never break even.
nothing from bfl was ever priced in btc, it was always USD. You're making the mistake of attempting to hold bfl accountable for the price change in btc...
Just to be the devil's advocate, what do you think BFL would have done should the value of BTC fallen by half instead of risen by ten times?
It doesn't matter what the BTC exchange rate is when you buy mining equipment. It also does not matter whether the exchange rate rises or falls. You can calculate whether or not you should purchase for any given set of difficulty growth rates and starting rate.
When you buy mining equipment you are making an investment in BTC. Buying ASIC mining equipment provides a variable amount of BTC. Buying the BTC from an exchange provides a fixed amount of BTC. If you get more BTC from mining than from buying BTC off an exchange, then mining
might be a good investment. If you get more BTC from the exchange than from buying mining equipment, then mining would be a bad investment.
BTC cannot have negative value, ergo (all other things being equal) more BTC is always better than less BTC.
Nobody is holding BFL responsible for the exchange rate.
BFL customers from June 2012 could not have predicted that their investment in BFL was inferior to purchasing BTC off an exchange because of the "Two More Weeks(TM)" marketing that went on.