Its 20$ for the first month normally, then 11-15$ per month after. Though, honestly, if you want to you can play it for free after 3 months (make enough ingame isk to buy 30-day gametime plexes every month, or 60 day GTC's every 2 months).
Now, if only there weren't many other games that I wanted to play, and that the monthly fee was 75% off :3
I want to get back into this, but I'm preoccupied...