Essentially, your UseHandlers class is your overall system. It should have one instance of the cash handler then 4 instances of the ticket handler (one for each route with separate prices for each)

Pick up the ticket type and then depending on what the price is, check for the appropriate amount of cash in the cash handler, if there's enough, check if there is enough tickets to buy one.
If both are OK, deduct the money from the cash handle r then reduce the ticket amount by one.

If I haven't explained it will enough, pm me and I'll explain again when I am on my pc not phone