I'm going to warped tour Pomona and planning to buy ticket at the gate but...?

I'm going to warped tour on July 1st at Pomona but i don't have a ticket yet. I tried looking online but it's too expensive compared to when you buy it at the gate, and it's kinda too late now if they're going to mail it to me. I'm just worried that if i do buy the ticket at the gate, they will sell out even before i get to the ticket booth. My friends already have their tickets printed out. If i'm not able to buy the ticket then i would have to wait outside until my friends get back, we will drive an hour and 30 mins to get there. Any suggestions? Should i still come and take my chances on buying the ticket at the gate or should i just not go at all? Feel free to make additional comments, etc.. Thank you so much! It will really help.