Qoo10 now has an offer for Majestic Ferry at $35.90. At the same time, it's giving a coupon worth $5 that can be used for minimum purchase of $30. Means the ticket net cost will be $30.90. If you have QPoint, you may apply up to 500 qpoints for additional discount, bringing it to $25.90.
I believe this is the lowest that can be found anywhere at this time.
Here's the link for the offer
http://www.qoo10.sg/su/414938072/QTALK/Q107807539