You are correct...there WILL be blood, and lots of it! But I personally think it's cool that people are smart enough to realize what your work's worth. I know I'd prefer to commission though, because then I know that YOU are getting the money.
That's my feeling too; There are a number of cards that i would have very much liked to have chased, but i really would rather go straight to the artist and support them that way. I could care less if it's an "official" card, personally, and i also think that 99% of the time, a straight-up commission comes out nicer anyway.