Just go to the TD Waterhouse Centre, park the car and you will be absolutely bombarded with ticket sellers just outside the main entrances and across the street.
I went last week and tickets were going from anywhere from $10 to $40 per ticket. Realize that these are not "authorized" ticket vendors, but the tickets are normally valid.
Realize that this is "LET THE BUYER BEWARE", but I sat next to a family of two who had bought two of the three tickets that the vendor had to sell. I bought the third ticket.
BTW, the venue is a great place to watch the games. At this time, the Magic just are not playing well. The last home game against the Knicks was possibly the worst the Magic could possibly play and still be called a professional team.
If you don't want to take any chances, just go to this web site to get tickets:
http://www.nba.com/magic/tickets/arena.html
If you do decide to buy from the ticket vendors outside, just print out the seating chart of the arena, and take that with you to locate the specific tickets that the vendors are selling. Again, this is a "LET THE BUYER BE AWARE" suggestion, but you can save a lot of money.