Four H-boards will do 140 GH/s with mild overclocking (the two I already have are doing 70). I paid about BTC1.87 yesterday for them. Five (for 175 GH/s) would've been about BTC2.34. "1/3 cheaper" may have been a little bit of an overstatement, but Bitfury hardware is now cheaper.
No, it's not. You're trying to compare overclocked incomplete Bitfury systems with stock clocked complete Antminer systems. That is not a valid comparison.