Fish Store

Question

For a long time I have been buying Chilean Sea Bass at a fancy fish store. It is completely filleted without any skin. After reading some of your replies, I am beginning to think that this is improper, and that while buying at the supermarket is OK, buying at a store, where the owner has a financial motivation to deceive, is improper. In fact, a local rabbi pointed to Yoreh Daeh 83:7-8 and 119:1 in support of this. On the other hand, I think that maybe since it is against the law to substitute a different fish, and if the man is found out it will destroy his business, that you can rely on his statement (not to mention the fact, that Chilean Sea bass has a distinctive taste.) I have been told that the latter point, whether we can assume that a merchant won't take a chance to damage his reputation is a dispute among poskim. What do you think? Should I give up going to the fish store?