Buy one, get the second at 50% off.
Code: GOB50Hogwarts castle light kit
When I finished my Lego Hogwarts castle kit I felt it was missing something. Adding this light kit has greatly improved the "wow" factor. Installation took quite a bit of time for a first timer but I managed to figure it out pretty well. If you spend a little extra time, you can hide most of the wires to give it a more finished look.
I had one bit light that was broken so I emailed customer service. They were able to send me a replacement within a couple weeks and absolutely no hassle.
I had a lot of fun putting this kit together and highly recommend it to anyone who wants to elevate their Lego sets without breaking the bank!