I've seen some really nice one on Reef Central but they've cost about $200 a pop and they're ligther in color than the one you posted.
There was someone on Reef Central that waited along time to get one and after he finally got it he had to sell it. He was a student he need to money for something else. It was really nice.
I think what you'll see is over time the price on these things will start to come down. Look at Rose anemone and Peppermint Hog that where very expense not to long ago and the price have come down on them. Same thing will happen on the Tear Drop clam as once they get in demand they'll be some one that will come up with a bunch for cheapier prices. What once was rare will not be somewhat common.