Put them side by side and compare. Is the pattern consistent in both, are the colors clear (allow for some very slight color variation between batches). Is the weave/thread count the same. Look at them from the wrong side to see if there is a difference in how the threads took the dye, as well as weave. If they are really close, then I would suspect that the mark up at the LQS is the normal high, and that the other store got a deal.