FM1 refers to the first AMD APU socket. On Newegg the "best" FM1 APU available right now is the 2.7 Ghz A4-3400 for $50. Not many are still available. On Ebay there is an A8 3870K 3.0 GHZ quad core for $99. From a bang for the buck perspective the A8 and A10 black edition models are considered top of the line.
Me? I'd go for an FM2 socket board with an Athlon 750K for $75.