score:5
Airliners or staff tickets are not available to regular passengers, they are strictly available to employees of different airlines. Each airlines provides each employee with certain or unlimited number of free/discounted tickets each year/contract depending on the contract or level of the employee.
In addition to that each airline may have a bilateral agreement with other airlines so employees of these airlines can get discounted space available tickets on the other airline, this is called ZED tickets. The process of getting such a ticket is not as easy as dropping by an airline's ticketing office and get one! it has to be issued from the employee's airline according to the agreement and it may have a special application to be filled and the person has to show proper airlines ID prior to boarding. These tickets usually are extremely cheap (around 90% discount or more) but it is seat available, I have saved a lot of money because of the ZED agreements, I also have faced a lot of delays when the planes are full and I couldn't get a seat.
Anyway, staff tickets are only available to airlines staff. For regular passengers I am not aware of any disounted "Space Available" tickets, the only way to go is the different offers and discounts from different airlines/websites.
Upvote:3
I'm not sure whether buying such tickets would be possible, but chances are that only 'full-cost' airlines will have such an option. For cheap flights, the best option by far within the South-East Asia region would be to fly with a budget airline. Wikivoyage has a list of discount airlines that operate in Asia.
If you have even a slight amount of planning though, and can book tickets online, you will find much better deals booking with low-cost airlines online as opposed to buying them at the airport, based on my personal experience with SEA low-cost airlines.