I'm going down there this weekend with the family and staying with my brother in Tempe ,, I know there is 4 ballparks within a close vicinity of his place where teams play (Oak, LAA, SF, and Cubs) ,,, for anyone that may know,, do these games typically sell out and should you buy ticketmaster tickets in advance?? or for the most part can you just walk up and buy tickets at the boxoffice,, thanks if you can help...