From what I understand, in solo mining, you don't make 1 BTC but rather the current reward of 50 BTC if you solve a block. The downside is that the difficulty is already high enough that even solo GPU mining with custom rigs stuffed with all of the high-end GPUs they can take could take years to solve one block. CPU mining was completely pointless long ago. You might be able to make a little BTC if you join a mining pool, where a bunch of miners agree to share the reward if any of them solve a block, but you probably still need some serious hardware to get anywhere.

Meanwhile, ASICs - custom-designed CPUs that do nothing but mine, are really expensive and also really fast - seem to be coming onto the market, and may make even pooled GPU mining pointless in the next few months.

Correct me if I'm wrong about anything, I'm still learning this stuff too...