Get your tickets closer to the date, depending on the market you're in and the teams that are playing. It can be risky but paid off big on my last trip.
Went to four games last December/January in NYC, DC and Oakland. Stubhub had tickets for all games at VERY reasonable prices. NBA ticket exchange can also be good but not as consistent Most expensive was in Brooklyn, $50USD for seats in the nosebleeds against the Bucks. Terrible game but great arena experience.
For Wizards games, was able to get floor seats about 8-10 rows behind the basket on Stubhub for around $25-40USD. Bought some a month or so before the trip and others while we were there the day of the game. Much depends on the demand and who the home team is playing, obviously the bigger the game the greater the cost.
Warriors games were much the same in terms of price, lower level seats for about $30USD. GSW games have by far the best atmosphere of any NBA arena I've been to which includes Barclays, TD Garden, Staples, Verizon and MSG. Subpar facilities by comparison but passion of the fans themselves can't be denied.
