the museum entry is free. I believe the times are from 10:30am until 5:30pm, on fridays is 2pm - 8pm - they're closed on Tuesdays.

If you're into art then leave youself a few hours to wonder around, there is quite a lot to see...

Compared to other "Islamic" museums around the world, this one is quite different. One of the best i've seen... Well worth the visit