@Achillefs *********
the onward ticket service gets you a ticket to show the airline staff that you have a departing ticket from Thailand. The reservation will be canceled either within 48 hours or 14 days of when you pay the company for the ticket. These ticket services are not designed to actually fly. They cost from about $10~$40 depending on the company and whether you get a ticket for 48 hours or 14 days. You can buy a 60 day round trip ticket back home, so long as you can show you will be leaving Thailand within the time of your visa. A simpler plan for you would be to apply for a 60-day tourist visa. Then you would not need to deal with an onward flight company.