Those that kept their BFL preorders, or even made new orders, look likely to come out ahead over avalon batch 3.
No! I paid nealry 200 BTC for a Single SC in June 2012. There is almost no chance to get this money back so in the end BFL was a bad investment. The Avalon batch 3 was sold for 80 BTC (?) and nearly the same hashrate. Avalon already delivered this kind of miners while BFL is still in the prototype state with the singles. It's quite realistiv that an Avalon batch 3 will reach break-even. For the BFL single I see no chance. Unfortunately I ordered a single (and a bASIC) and not an Avalon so bitcoin mining is history for me before it even started.