For what date to purchase airline ticket to prove departure intent after B-2 v

[arielle777]

I have been a student in the U.S. for the past 8 years, the first 7 years in F-1 status and the last year in M-1 status. My M-1 visa expires in July. I would like to travel a bit after my visa expires so I will try to change my status to B-2. In order to prove that I intend to leave the US after my vacation, I plan to purchase a one-way ticket. For what date do I need to buy the ticket? For a date in July, when my M-1 status expires, or for a date in November, when my planned vacation ends (in case my change of status to B-2 is approved)? I saw that the air fare to November costs half as much. So I would prefer to purchase a ticket for November and then change it to an earlier date in case my application is not approved. But is this the best thing to do?

[immihelp]

November.