The Yankees are raising the prices of some of their most expensive tickets for 2011 after making big cuts in 2010. They are also hiking the cost of bleacher seats for only the third time in 13 years. The price of the best field-level seats will rise to $260 as part of season ticket plans, the team said Monday. Those seats cost $250 this year. Bleacher seats that had been $12 increase to $15, while $5 bleacher seats remain the same.