Is there a certain game you're looking to go to?
If you're going in March, the C's home games are:
Warriors
Jazz
Grizzlies
Magic
76ers
Pistons
Heat
Clippers
While the Clippers game might be a tougher ticket to get, people will probably be practically giving away tickets to everyone else except maybe the Warriors.
Depending on what game you want, you'll probably be able to get tickets much cheaper if you wait till right before the game (anything from a few days before till the day of). You'll be able to walk right up to the box office, or even grab something under face value on stubhub, ebay, ticketmaster's ticket exchange, or even craigslist (though craigslist is a little riskier if you're not used to dealing with it). C's tickets won't be tough to get at all, especially if Rondo is moved at the deadline.