My husband and I did the "Let's Shop and Bargain" tour with Merve, and are so glad we did! We were really trying to make the most of each day we had in Istanbul, and the Grand Bazaar is quite big and overwhelming the first time you go in - we honestly didn't have an entire day to devote to going to each stall and trying to figure out who had the lowest prices. Merve knew where to take us for each item on our list, so we never got lost once. Also - don't underestimate how helpful it is to have a native Turkish speaker to bridge some of the language gaps and negotiate the prices (most of the sellers spoke some English, but there were times when we were describing what we were looking for in detail, and she was able to convey that with no problem).
Finally, let me just say that Merve is such a genuinely sweet person. We left feeling like we had a friend in Istanbul! Don't miss out on this tour!