It depends. If you want to see HDDR, and you have the credits, then it is a smart use of the credits.
Sure you could use those two credits and have meals that would cost you more than the price of HDDR. But getting hung up on the price you *aren't* paying is silly in my book. As long as you prefer one trip to HDDR over two other TS restaurants, it's the thing to do.
On the other hand, if eating at HDDR is going to use up credits and you are going to have to pay out-of-pocket for meals at TS restaurants, then it probably does make more sense to pay out of pocket for HDDR.