Buy bus ticket at Kawaguchiko 5th station?

I am taking a bus from Shinjuku directly to Kawaguchiko 5th station. Can I buy a bus ticket in 5th station to go down to Kawaguchiko Station? I am going to take a bus back to Shinjuku from Kawaguchiko Station. Appreciate the advice.

Yes, it is possible, provided that the bus is not fully booked out. In the worst case, you could take a regular bus down to Kawaguchiko Station and catch a bus or train from there back to Tokyo.

Thank you Uji. What is the difference of the regular and non regular bus? Is there a timetable for these buses? I have looked up in the websites and can't seem to find any. A friend advised to take the train as it is cheaper. Which is the more affordable transport?