Seems like playing with Pi is playing with Pi, might as well build a Pi retro gamer or home security system
Gotta agree with the pool suggestion.
Either you have a data center to chase the hash or you join the equivelant in a respected pool.
Then you can spend that time on learning more about the awesome bit commerce market to be ready for whatever phase you need to be ready for because the changes have just begun.
There's also alt coins to mine and BTC conversion to/fro.
So much more than Pi rev B
Just my honest opinion
Here to collaborate not dominate
I think learning command line for CGMiner or BFGMiner is not a bad thing for when learning. The RPI just makes sense as uses so little electricity. And throw in a hub and a few sticks, you can learn a lot about mining without a huge cost.
Or yes you can get a big miner. But if you do I don't think GUI of a modern miner teaches you as much as command line.