I think you just select a donation amount..
You are buying ONE donation of "n" number of tickets...
For instance, if you were buying ONE ticket, you pay $35. If you were buying 2 tickets, you put in $70...
You see, ONE donation for "n" number of dollars......
You are not putting items in a shopping basket... so, you are donating to ONE thing.. that is the "1" you are curious about.. now you just
put in the amount you want to donate..
1 tix = 35
2 tix = 70
3 tix = 105
etc......
But you don't put a "quanitity".. the amount you donate assumes a ticket quantity.