WOOOOOOOOOOOOO HOOOOOOOOOOOOOOOOO!!!!! I could BE RICH!!!!
I hope.... 
I'm obviously not going to charge $200 for 2 hours of my time, I am still a Uni student, and only turning 21 soon. But If I could charge that in say 10 years time.... LUCKY ME!!!!!
$$$
Of course, the problem would be finding enough songs to transcribe for people. Eventually, one or the other (or maybe both) of these things will occur: 1) you'll run out of songs to transcribe, or 2) you'll run out of people who want transcriptions. When you run out of potential customers, then you'll be forced to enter advertising (if, of course, you would want to make a career out of this). And advertising costs money....a lot of it.
And, like dkaplowitz said, I find it hard to believe that anyone would pay 200$ for a transcription...especially for an elvis song. For a little more than that, I could buy Garritan Personal Orchestra and make my own good-sounding symphonies, or buy Garritan Big Band & Jazz software and create realistic-sounding jazz songs. $200....for one song? When for $250 I could make my own symphonies? I don't know....just don't get your hopes up. (And, of course, there's gotta be sheet music out there...even if it's for guitar, anyone with half a clue about how the piano works could transcribe it himself.)
Terry