Up front where the rich folks sit, with a beggar's billfold -- what more could an economically challenged sophisticate desire? Pick your poison: Jascha Heifetz playing Beethoven? Pinchas Zuckerman interpreting Bach? A great symphony, a play, a musical? You aren't going to fork over $70 to $100 for the best seats in this splendid Broward County house of culture on the New River, because you can't. You're a waitress. So here's what you do instead. Count out $20, even if you have to use your laundry quarters. Arrive near the ticket windows about 20 minutes before showtime. Look carefully at the crowd. A few well-dressed aficionados are standing around restively, trying to make eye contact. A come-on? Naw. You're probably looking at a rich-guy-turned-scalper with a couple of tickets worth more than your old car. The trick is to tell him up front exactly what you'll pay. Sometimes you can find yourself three or four rows back from one of the world's great performers when the first notes ring out. So what if you have to wear dirty clothes for a few days?