Booked hostel through them. Showed the prise as everybody else including tax, charged part for the reservation, the rest payable in place.
The place charged almost full price again.
Contacted hostelworld a week later, a rude representative started changing story and giving random excuses, maybe it is pending charge, maybe tax was not included (even if Booking conditions clearly state it is included), just any random nonsense you can figure out to push customer away.
Stay away unless you are looking for embarrassment and waste of time. Just charge back with your bank in case of problems as it doesn't the company would approach problems in good faith.