It depends....
1) Do you have the money laying around?
2) What would you do with the money if you didn't buy AP?
3) Would you put it on a CC and carry the balance for a while?
Think of it this way, if the AP price rises lets say 3%, you can think of it as getting an interest rate of 3% on your money.
For example, lets say it would could you $1000 today to buy the AP's, but if you wait til one year from today it would cost you $1030.
Now, if you :
a) put that money into a savings account (or whatever) that nets you 3% interest a year, it doesn't matter what you choose to do because the end result is the same. You can put $1000 into the bank and it will accumulate to $1030 in a year and then buy your tickets or you can buy them now.
b) if you can't get 3% return then you'd be better of buying the tickets now.
c) if you can get greater than 3% (say 12% from paying off some of the balance on a CC) then you're better of waiting to buy the tickets.
Of course a and c only work if you're not going to go into those savings and use that money for something else (or put the balance right back onto your CC by buying something else).
d) if you don't have the cash laying around and plan on putting it on a credit card only do so if 1) you're getting 0% interest or 2) You plan on paying it off immediately (within 2 months)