Link:
http://newyork.yankees.mlb.com/ticketing/singlegame.jsp?c_id=nyyMastercard Presale ends tonight (Feb 21st 2016) at 10pm EST.
Any Mastercard should work.
$5 Games +$1 per ticket fee (3 tix were $21.30 total)
Apr 6 vs Houston Astros (7pm)
May 10 vs KC Royals (7pm)
Sept 5 vs TOR BlueJays (1pm)
Half-Priced Games Quick search showed it as $11 tickets + fees:
Jun 22 vs COL Rockies (1pm)
Jun 30 vs TEX Rangers (1pm)
Jul 21 vs Bal Orioles (1pm)
Aug 17 vs TOR Bluejays (1pm)