As long as I've been a computer head, if the guy provides the source for free along with the offer to sell you a pre-compiled binary, then you are paying for..
1) The convenience of having it pre-compiled (and in this case, re-coded )
2) Your stupidity or lazyness , because you should not 'download' pre-compiled binaries from semi-anonymous people.
Sure, it seems like a rip-off, but paying for a lesson is how the world goes round.
I just noticed that. LOCK!