Absolutely worth seeing for its historical significance and stunning exterior, but with the steep ticket prices for foreigners, it might be wiser to admire it from the outside and view the interior online. There are better ways to spend your money in Istanbul.
Definitely a place to visit and a must for every tourist at least once. I loved both the exterior and interior, the audio guide was great and I’ve learned a lot. The view on Bosporus is breathtaking!